Please help, anyone who can.

I am having problems with any of my programs crashing when i try to convert from .avi or .wmv to Mpeg2. I am using TMPGEnc, Ulead DVDMF3, WinMPG converter.....etc. I keep getting the Windows message:
" (program) has encountered an error and must shut down...."

Does anyone know what this is? How can i fix it? I tried installing some new codecs, but I'm definitly missing something. I also tried to fix the files with a repair program too, and the same thing. also, ones strait from VCD encounter it too. any info would be greatly appreciated.

Also, with TMPGEnc, i cannot load a .asf or .wmv file. My Direct Show is up at 2, any help with this one as well? Thanks guys.