Access repeatedly crashes.

Does anyone have any suggestions to help my figure out why Access
repeatedly 
crashes when I do very inocuous things? Like change the Control Source on
a 
text box or other equally mundane stuff?

I've tried to uninstall and completely remove all references in the
registry 
and then reinstall. But after a while it starts failing again. I don't
know 
what might be happenig to Access or my system to induce this.

Any suggestions would be greatly appreciated. I sure hope I don't need to 
resort to a reinstall of my system....

BTW, I'm also having a problem with the VB help system where links in the 
topics aren't displayed or generate script errors.

John S.