Oracle 10g works fine with oracle 8i clients. SQL plus, toad, they connect fine using the oracle 8i client.
But there are some reasons why it’s a good idea to move to Oracle 10g client.
1) Oracle 10g has an instant client which is very light 254 KB compared to 259MB for the runtime client.
2) Oracle 8i is getting a bit old and won’t be supported anymore.
3) It’s good to have some homogeneity in the IT parc. (at least for Oracle,not for printers but that’s another history)
So, I’ve been testing the instant client a bit because I found it cool.
It install just the basic to connect using TNS or ODBC. It doesn’t install any tools of its own. It means that when you install that client you might have some tools or application of your own to work with.
Things to know when Installing 10g instant client
1) After installing the Oracle 10g instant client, a new environment variable must be created.
Go to control panel> system> advanced tab> Environment variable.
Create a new system variable called TNS_ADMIN.
In the Value field, put the path where your tnsnames.ora and sqlnet.ora will be located.
Note: If you already have a folder called like that from Oracle forms for example, just point to that folder. It makes less work for future maintenance.
2) Very often, if not all the time, after installing the client, I tried to create my first Oracle 10g ODBC.But I got the following error message:
“The setup routines for the Oracle in instantclient10_2 ODBC Driver could not be loaded due to system error code 126”
followed by:
“Could not load the setup or translator library”
Well it’s an error, let’s check Metalink to see what they say about it.
Brilliant! They describe the error exactly as I have it.
Here is the article. You will need a metalink login to get it.
What Oracle say
Cause
This error may occur for the following two reasons.
1. There is not a mfc71.dll and msvcrt.dll located on the pc that the Instant Client is installed on.
2. The directory that mfc71.dll and msvcrt.dll is in is not included in the path environment variable.
and
Solution
To implement the solution, please execute the following steps:
1. Find the mfc71.dll and msvcrt.dll if it on your pc and include the directory in which it is in in the path variable. It is normally found in the C:\WINDOWS\system32 directory. Or copy mfc71.dll and msvcrt.dll to the directory where the instant client is installed.
2. If you have installed the full Oracle Client and ODBC Drivers for version 10.2.0.1 both mfc71.dll and msvcrt.dll are located in the ORACLE_HOME\bin directory
It couldn’t be that easy
Ok. First of all I check if the two dlls are on my test computer. I check ORACLE_HOME\bin
None of them are in it. So it seems the instant client doesn’t install a couple of required dlls. But apparently windows should have it.
If it is, there are 2 solutions:
a) Modify the “path” variable in Control Panel>System>advance tab> environment variable> system variable and add the path where the dll should be. Logically it’s C:\windows\system32.
b) Copy the dlls from C:\windows\system32 to the location specify in the “path” environment described at point a)
OK let’s copy them: I found msvcrt.dll but there was no mfc71.dll in system32. I’m using Windows XP. I’ve tried with Windows 2000 too.
I had a runtime client installed on my computer to manage oracle. I decide to copy them from the bin folder on my computer and into the location specified in “path” on the test computer.
I have to admit at that point that I thought it would work. Well it didn’t.
I finally cleaned up the instant client installation 254KB and installed the runtime client 259MB.
Then I wanted to create my finally working ODBC connection.
Oupsy: There’s no ODBC driver installed with the runtime client.
But this time it’s easy.
On top of that runtime client, make a new installation but this time customized, make sure to use the same home. Locate Oracle 10g ODBC and install it.
Finally, it’s possible to enjoy the new ODBC driver.
Summary
To get Oracle 10g ODBC driver installed and working on your computer:
1) Install Oracle runtime client
2) Install Oracle 10g ODBC driver on top of that using a customized installation.
The Tendjee 
I follow your instructions above and got “ORA-12154: TNS: could not resolve the connect identifier specified” when I tried to connect.
hi Daniel,
I would need to know a bit more about what you have installed in order to help you.
ORA-12154 however is a problem with your tnsnames.ora file
If you are using instant client make sure you have specified the path in your system environment variable.
It might also be a configuration problem inside your tnsnames.ora.
Your configuration of Oracle runtime might be good already.
I went through the initial Oracle installation and followed that process up with the suggestions above and still the error “The setup routines for the Oracle in instantclient10_2 ODBC Driver could not be loaded due to system error code 126″ keeps coming up…
TSNames placed, envronment variables set, paths adjusted, dlls positioned, ODBC drivers installed etc (even a reboot and a full registry check) have all been tried a number of times. There must be some small issues that is stopping the application from finding the dlls.
Would virtual PC, MS windows 2003 be an issue?
It is just no working… but at least it is consistent.
There was one file that had been overlooking in the solution. It is apparently a 16 bit dll as it is normally stored in the windwos system directory. Th file name is ‘msvcr71.dll’. As soon as reference was provided to this file everything worked.
Hi Jim,
thanks a lot for this information. How did you found that!
Hi,
My application hangs when i’m connecting to a 10g server from Windows 2003 server. The same application works fine if the application is installed in a windows 2000 server. The application is a VB application. The process involves lot of queries. Basically it creates lot of tables. The process does not fail a particular query. it is random.
Could you please tell if there is any specific setting that needs to be done for Windows 2003.
Thanks in advance,
Karthik.
Hi.
I need a little more informations first:
1) On what platform is your server running?
2) On what platform is your client running (even if the client is a server)
3) What connection method are you using?
4) Have you installed oracle 10g instant client or is it an 8i client (8i client can run with 10g DB for tns connection but not ODBC)
let me know your answers. I’ll try to help with that.
Thanks for posting here.
Tnxs. Your env. variables comment comment help me. It works, so I calm me down.
HI,
CAN YOU TELL ME WHAT TO PUT IN THE VARIABLE VALUE IN THE ENVIRONMENT VARIABLE… I FOLLOWED YOUR PROCESS BUT I CANT FIND THE TNS WHEN IM CREATING AN ODBC… THANKZ
Concerning the environment variable,
the variable to create is:
TNS_ADMIN
The value is:
the location of te tnsnames.ora (c:\oracle\product\102\network\admin for example)
Thank you very much. This is exactly I was looking for.
This really helped , I am unix / linux guy not a windows guy. Thank U very much
i tried it, but still get error.. 😦
Copying the missing mfc71.dll from an XP-System to the failing 2003-Machine worked for me! (msvcrt.dll was already present on 2003)
Excellent. Saved my day!
Very Thanks to this solution.
“Oupsy: There’s no ODBC driver installed with the runtime client.”
That little tidbit saved my life. Thank you, sir!
Hello Nicolas,
I am new to oracle.I installed oracle client on my windows m/c, created an environment variable
TNS_ADMIN = C:\oracle\product\10.2.0\client_1\NETWORK\ADMINTITLE.
1)I am not able to ping the server from my local machine.But from other server i am able to ping the oracle server.
2)When i am trying to test the service through NetManager i am gettig error
The test did not succeed.
ORA-12170: TNS:Connect timeout occurred
There may be an error in the fields entered,
or the server may not be ready for a connection.
3) While testing the ODBC connection following error is thrown :
ORA – 12170: TNS:Connection Timeout occured
—————————
Testing Connection
—————————
Unable to connect
SQLState=S1000
[Oracle][ODBC][Ora]ORA-12170: TNS:Connect timeout occurred
—————————
OK
—————————
Please let me know what all settings are required for making the client work. Please help me out with this.
Thanks & Regards
Ruby Agarwal
I got an error that it couldn’t append to the PATH variable because it was too long, and when I tried to add an Oracle datasource :-setup routine could not be loaded due to system error code 988. Please suggest what to do ?
Can i just install the oracle provider and will it work? Or client is also necessay?
Hi. If you want to use ODBC for Oracle, the easiest way would be to install the Oracle runtime client.
Oracle instant client is a bit special and requires special care. If you follow the instructions above, you should be able to get it to work.
Nico
I had the same issue but was trying to use the 11g instant client in a VirtualPC image of XP Pro. I skipped all the BS about the dlls as I already had tried copying those and it did nothing. What you said in the summary was the fix – thanks!
Hi ,
We are using secure oracle 10g instant client on windows XP and using oracle 10g server enterprise edition on Linux machine.
We are running query using VB application. But our application hangs if we keep it open for 10-15 minutes. We are facing this issue when we use oracle client on secure layer(2484). It works fine if we use oracle client without security(1521).
What could be reason ? Any ideas…
Thanks in advance ,
Gaurav
I tried setting up the 11.1 instant client but was unable to get it to work with Toad 8.6. I than tried 10.2 instant client and it worked fine.
hi…im newbie in oracle
i try with hard connection to oracle in win 2003 via NAVICAT ( client tools ) in the same PC (localhost) but it doesnt connect …. i have downloaded instantclient oracle
i have extracted it in “c:\instantclient” so the result is “c:\instanclient\instantclient_10_2\….any file”
and i have set the environment variable “PATH” like this “C:\instantclient” for instantclient
and TNS_ADMIN “C:\oraclexe\app\oracle\product\10.2.0\server\NETWORK\ADMIN” but it still not connect…” please help me…
thanks.
Thanks!
Good resource!
BTW: Could you faced with unstable connection – sporadically getting ORA-12545?
brgds
Janeks
I found what is the reason, for that sporadic error:
Despite I have in tnsnames.ora only IP addreses I need to have them also in hosts file.
Now it just works.
THANKS A LOT!!!!!!
One week to find this site, now it works!
Hermann
Thank you very much for the adding the system variable property for having windows find the tnsnames.ora and sqlnet.ora files for the Toad log on (ORA-12154 error message). I did not think I was going to find a solution.
Cool…I was getting ORA-12154 but when I defined the TNS_ADMIN env variable it got resolved. Thanks for posting useful details.
ODBC had error code 126 after installing “ODTwithODAC1110621.zip” (setup.exe inside, of course). Resolved by copying file mfc71.dll to client_1 directory.
It seems this DLL is still missing in installation package.
Setting TNS_ADMIN resolved my “ORA-12154 error” , i think this variable is mandatory for 10G client users.
you are a god send, downloaded mfc71.dll and it worked thanks man 🙂
I wish more people would explain these things like you did. Great work! Fixed my problem
Thank you for this explanation and assistance, but
When I download the Instant Client Package – Basic (instantclient-basic-win32-10.2.0.4.zip) it does not contain the files (mfc71.dll and msvcr71.dll and TNSNAMES.ORA) how we get it?
Thank you again
Very Good! Bro Thanks!!! It works for me 🙂
Hi All,
Following problem got solved by applying Oracle Patch 7118478 (100% CPU) on server side.
We are using secure oracle 10g instant client on windows XP and using oracle 10g server enterprise edition on Linux machine.
We are running query using VB application. But our application hangs if we keep it open for 10-15 minutes. We are facing this issue when we use oracle client on secure layer(2484). It works fine if we use oracle client without security(1521).
One more thing
We want to use instant client by not setting TNS_ADMIN and SQL_PATH variable but by keeping “installation files and binaries which uses database” at same path.
will it work? Can anyone provide search order for tnsnames.ora and sqlnet.ora files ?
Thanks in advance,
Gaurav
We want to use oracle instant client by not setting TNS_ADMIN and SQL_PATH variables but by keeping “installing files and binaries which uses database” in the same directory. Will it work? what is search order to find “tnsnames.ora” and “sqlnet.ora” files…
Thanks in advance,
Gaurav
“Create a new system variable called TNS_ADMIN.”
That was all I had to do! Thank you so much..
I recently came across your blog and have been reading along. I thought I would leave my first comment.
I don’t know what to say except that I have enjoyed reading. Nice blog. I will keep visiting this blog very often.
Thank You
PowerBuilder Application development
Thanks, this article really helped me!!!!
Awesome! it worked!
Hello im trying to install oracle instant client and odbc packages
when i extract them both have the same name
so can any one guide how do i go about making work
after windows 2003 server SP2 OS installation, I Changed my system host name .but this time it’s not connecting ORCLE hostname and CS6.5 host name. already I created TNS_ADMIN, but this error came( ORA-12154 TNS: could not resolve the connect identifier specified ).please help me how to coneect correct host name.This is my mistake (old hostname=hari-212345 but I changed new hostname=admin)..please again once help me.
after windows 2003 server SP2 OS installation, I Changed my system host name .but this time it’s not connecting ORCLE hostname and CS6.5 host name. already I created TNS_ADMIN, but this error came( ORA-12154 TNS: could not resolve the connect identifier specified ).please help me how to coneect correct host name.This is my mistake (old hostname=hari-212345 but I changed new hostname=admin)..please again once help me.
I follow the instructions but got “The setup routines for the Oracle in OracClient10g_home1 ODBC driver could not be loaded due to sytem error code 126.”
I read this paragraph fully about the difference of
most up-to-date and previous technologies, it’s awesome article.
There are definitely numerous particulars like that to
take into consideration. That is a great point to carry up.
I supply the ideas above as basic inspiration but clearly there
are questions like the one you convey up where crucial factor will likely be working in sincere good faith.
I don?t know if best practices have emerged around
issues like that, but I’m sure that your job is clearly recognized as a fair game. Each girls and boys really feel the impression of just a moment’s pleasure, for the remainder of their lives.
Dan Oh Well, if we remove hydro solar energy sources, such as massive wind
turbines. While solar and wind investment, respectively.
Whether consciously or unconsciously, you are told to mute that string with your strumming hand on the fret board to produce
multiple notations and different sounds. New gig bags for trombone for 2012!
The process is compressed into 3 minutes and annotated in a way that translates into equal opportunity.
Good site you’ve got in here.
Hi to every body, it’s my first visit of this blog; this webpage consists of awesome and genuinely fine information designed for readers.
hey there and thank you for your info – I have certainly picked up anything new from right here.
I did however expertise some technical issues using this site,
since I experienced to reload the web site many times
previous to I could get it to load properly. I had been wondering if your hosting is OK?
Not that I am complaining, but slow loading instances times will
sometimes affect your placement in google and
can damage your high-quality score if advertising and marketing with Adwords.
Well I’m adding this RSS to my e-mail and could look out for a lot more of your respective interesting content. Ensure that you update this again very soon.
Ok, a few errors about the latest drivers from Oracle needing MSVCR71.dll when trying to add a DSN via OBDC Administrator – The latest drivers require version 10 of the Microsoft Visual C Runtimes. You can download this from Microsoft for free… The downgrading tip only works because it only requires MSVCR71.dll… I used FileMon from Sysinternals to identify what was upsetting Windows…
Thanks David! We installed latest Oracle Instant Client and ODBC driver (both versions 12.1.0.1.0) and were getting this system error code 126. Downloading and installing Microsoft Visual C++ 2010 Redistributable Package (x86) from Microsoft did the trick.
Thank you both Nico and Jim Lawrence. I was trying to setup a the 32 bit ODBC connection to the Oracle database on a Windows Server 2008 R2. Followed Nico’s steps and then copied the msvcr71.dll to the location where the sqora32.dll is located.
The brick and mortar casinos to perform these games slots casino at cost-free of expense.
Since, internet websites have lots of fun here while gambling through the thrilling games of
this site. Many individuals are suffering from
any style for your accent and also implemented their particular put icons.
Wonderful beat ! I wish to apprentice while you amend your site,
how could i subscribe for a blog site? The account aided me
a acceptable deal. I had been a little bit acquainted of this your broadcast offered bright clear concept
porn movie, porn, rough sex, hard anal, brutal rape
Hi, I think your site might be having browser compatibility issues.
When I look at your website in Opera, it looks fine but when opening in Internet Explorer, it has
some overlapping. I just wanted to give you a quick
heads up! Other then that, very good blog!
I do agree with all the ideas you’ve offered in your post.
They’re very convincing and will definitely work. Nonetheless, the posts are very brief for starters.
May you please lengthen them a bit from subsequent time?
Thank you for the post.
I know this web page offers quality based articles or reviews and additional
data, is there any other site which presents such information in quality?