I haven't done desktop support in a while, and I've never heard of the file sir32.exe, so I've got no idea what it does.
What operating system are you running?
I've checked
support.microsoft.com and can't see any info there.
I suggest you extract the original sir.exe file from your Windows cab files (if it's an MS file).. that's for Win9x/Me... or extract it from the i386 folder on your WinNT/2000 CD.
Also try Safe mode, does the problem still occur then? if not, remove all th 3rd party software you have installed... maybe one of your apps is causing the problem. I'm guessing this file is related to a program you have installed.
Empty your recycle bin..
All outta ideas. Good luck.
HOLD ON: BINGO! just found something.. you've got a virus/worm. Check out:
Virus URL I found
Regards,