Microsoft Office Menu’s Very Slow

Hello,
It seems that every time I go and try and open a Menu, whether it’s in Outlook or Microsoft Word or Excel, they drop down extremely slow. This is very weird because memory is not an issue. I am running a Pentium III with 256 megs of ram and have never had a problem running any program. These menu’s used to drop down really fast, until a week ago. What could I have done to make this happen? Is there any way to fix this?