oracle 10G forms connection with Oracle database 10G Enterprise Edition in windows 7
The message is an indication of incompatibility of Forms version that you're using with your OS, i.e. Windows 7.

You'll need to install Oracle Forms version 10.1.2.0.2 with patchset 3 to have this corrected. 

Else you can also install Oracle Forms 11g R2 which is certified for Windows 7