Explorer.EXE unable to locate component BROWSEUI.dll

Hello,

I'm having a problem all the sudden which started with the internet ,signing in my server [msn] would come on then go right off. Then when I tried to sign-on the welcome sign-on for windows xp would come up but any of the user icons I would open the error Explorer.EXE-unable to locate componet BROWSEI.dll
I was hoping to find out how to fix this problem fairly quick and I've already spent hours on the phone trying to talk to some-one at dell. I didn't know if there was a repair program I could buy to solve this or not? any information would be greatly appreciated

Thank-you
Dale