I uses Illustrator 10 on Windows 7 everyday at work, for some reason it will not open today. I have tried to reboot my computer and uninstall/reinstall the program without success.
It could very well be a preference corruption.
You may try to Move the folder with Illustrator closed (click Move the folder when you have followed the link).
This is a reversible way of resetting the preferences to the defaults; they are not reset when you uninstall and reinstall.