I have recently found that Windows service pack 1 has somehow fanished from my pc.I can remember downloading it some months ago,but it's now nowhere to be seen.I've checked in control panel add/remove programs,and there are other hot-fix listings there,but no service pack.I've tried to download it again,but the windows update site will not allow me to do this because service pack 1 controlls the ability to use the update system.This is really frustrating,how can i download service pack 1 again?
Right click My Computer and select Properties. Under the General tab, it should say what operating system is loaded and what service pack. If it mentions SP1, then it's been installed, and I wouldn't worry about not seeing it any more in Add/Remove Programs.
If you want to download the full sp1 (now called sp1a) again, click here and select Network Installation.