File association for exe (SirC32.exe)

My NT 4.0 Workstation will not execute programs when double clicking on an executable (.exe extension). I get an error message saying “Windows cannot find SirC32.exe. This program is needed for opening files of type Application”. Luckily, I can boot and run Windows Explorer. Sure enough, when I view file associations, the system has been modified to associate this SirC32 with applications. Unfortunately, it is the only file type that cannot be changed. It is greyed out.

I can run command to get to the command prompt and can run regedt32. But I am not sure if it is working properly.

Any suggestions would be greatly appreciated.