This is very frustrating.  I have loaded the PSQL v9 client (and unloaded it, and reloaded it). This is the error message I get. I have 20+ Desktop PC's that all have sucessfully accepted this client  with no major problem. I have checked the path and it is correct. This computer has XPPro and is identical with two other computers which work fine. Any suggestions?
 
I also get this error on a W98Se PC  
 
A couple of PC's with W98Se had errors  in the path that were put there by the PSQL install program.   I corrected the errors in the Autoexec.bat, rebooted and they work now. The Set paths had a \ left out between as: "pvswbin\..."

Charlie,
 
The only thing I know of with error 12 is it is definitely path related.  Is the error followed by another error mentioning a filename? When are you getting the error exactly?  Sometimes this error can be the result of a missing file. If it's mentioning a specific file, see if you can find it in the directory.

After many hours of messing with this problem, I have narrowed it down to either DBA, Novell Client32, or Windows updates.
 
If I uninstall the Novell Client and load the Windows Netware Service, DBA will work for me.
 
I was never able to get the W98SE machines working (not just a path problem).
 
I had two PC,s (New Ones with XP Pro) that had been working with DBA and the Novell Client32 all along that suddenly started to give me the error 12 message.  Again, had to change Netware clients to get DBA to work.
 
Novell Client/Windows XP Pro/??? do not seem to be working together.