Oracle 8.1.7 and Developer 2000 Version 6

I had Oracle 8.1.7 on Window 2000 machine. It was working pefectly. But when I installed Developer 2000 Version 6, I cannot access my database. Cant start svrmgrl, cant start listener. I have tried resetting all the environment variables. But no use. When I try to start svrmgr, it just hangs. When I try to start listener, it shows following message:

Failed to start service, error 997.
TNS-12536: TNS: operation would block
TNS-12560: TNS: protocol adapter error
TNS-00506: Operation would block
32-bit Windows Error: 997: Unknown error

I cant even uninstall Developer 2000 from the machine now. When I try to uninstall, it just jumps out.

Has anybody faced this problem?

No one has solution??