Currently, the most common cause of the temp2.exe error is the worm infestation. There could be others.
Run antivirus and antispyware scans... AVG, Panda, Trend Micro, Computer Associates EZ Armor, Symantec all have free scans. This will help you rule out the worm, or tell you how to fix it.
What you appear to have is the irc.momma worm... and a good, updated security software should be able to remove it... although don't count on Norton or McAfee to do so.