"you will need to install the Service Releases"
You didn't DL them and burn them to CDs?

Your loss mate.....

" A minor problem with reinstalling the OS is that it's almost never necessary"
Ya... right... that's why techies recommend a reinstall ever 6 months to a year depending on how much software you're installing/removing.... cause it's almost never necessary.... sure..... whatever.....

SRS.... do yourself a favour.... back up your important stuff and wipe your HD and reinstall..... You'll be happy you did... and your PC will love you for it