ok i assumed that you have sp2 installed, because steps have been tried only on it cause it saves the downlaod updates
you can save the installation for individual update you have installed
go to C:\WINDOWS\SoftwareDistribution\Download
this folder contains the dowloaded files from windows update
copy the files from there to any new folder,
now in the newly copied files you can see the information about the files by seeing their properties,Version
most of the windows update are self installing files so rename all the files with .exe extension and their you are they work, the installation works fine
some files are not .exe files and if they dont work, try.cab for them but i dont know how to install them
their will be one 38 kb file which is eula for sp2 so you can read it with notepad and rename it txt,
their will be one 45 Kb file which is .cab and i dont know what it is for
the other files willl be downloaded updates so you should first rename all of them as .exe and try,if they work fine else try .cab
for me all the files are .exe except for my sound card drivers update which is again .cab
now save alll those working exe updates to safe location and reinstall windows
after reinstallation is complete use the saved updates and after that visit windows updates for those updates which were in .cab format and we were not able to save them
i think this post is more reliable than previous one