It can be the legitimate Microsoft program related to Windows update, but it has been reported it can be malware also: www.auditmypc.com/process/wuauclt.asp
Things to do:
1. Right click>properties>version tab, and see what it says. Microsoft programs generally disclose details there.
2. Have the file checked by your antivirus program.
3. If you're sure you don't want it to run (even if it is legitimate): just rename it (if it's running in normal mode, do it in Safe mode).
Hope this helps.
every now and then there is a process in my task manager called wuauclt.exe and it takes a lot of memory and freezes the computer almost. got two of these files. one in system32 folder other in prefetch folder. the 1 in preftech folder is called wuauclt.exe-399A8E72.pf. what's this all about? read that it has to do with windows update but i have wud disabled. any recs as for what to do about this?