Just re-apply service pack 1, and hit the MS update page afterwords. You may be prompted for your install media, depending on your config.
Virii are becoming more and more innocuous*, the bad guys are realizing it's better for them to use the infected pc rather than destroy it. The loss of notepad and the restore points just wipes the evidence that it was installed.
*Al Pacino gives a classic definition of innocuous in Devil's Advocate - for those who've seen it...
