Computer Question: DLLHost.exe

I have a new HP Laptop, with a 2.2 ghz processor and, I think, 256 mb of RAM, running on Windows XP. I recently moved into the dorms for college, where the tech guys set up the ethernet for me. At home I had a plain old dial-up, and never had any problems with it besides prehistoric slowness. At school, however, when I go on the Internet it takes several minutes to even scroll down a loaded page, and when I try to type something the cursor and words lag far behind my typing. I’ve tried closing all of my background programs like AIM and MSN, but it didn’t speed anything up. I did Ctrl+Alt+Del, and found that a program called DLLHost.exe was using up to 99% (!) of my CPU. When I forced it closed, my Internet and everything else worked perfectly.

So, my question is this: What is DLLHost.exe, and what effect does my closing it have on the computer? Is there any way I can make it just go away, or will I have to continue doing this everytime I reboot? Am I possibly damaging anything? If the program is an unnecessary as it seems to be, why did Tech activate it in the first place?

Thanks in advance!

It’s probably the Msblast.D virus, pretending to be the legitimate Windows file dllhost.exe.

Do you have an updated anti-virus software ? It’s most probably the W32.Welchia virus.

Removal instructions:

Note that DLLHost.exe (virus) and dllhost.exe (legitimate windows file) are actually two different files located in two different directories. Do not delete the latter.