Problem with menus, folders, programs not opening up sometimes.

[Zepher]

I've started to notice that when I have a lot of folders open and a few Internet Explorer windows open that some programs won't load. Photoshop gives me a hardware error.
When you right click, no menu will pop up either.

I normally run with 5 folders open all the time, unless this problem pops up and I have start closing them.

any ideas what could be causing this?

Machine is the P3 750mhz in my sig.