This one took me a couple of hours to figure out and did a lot of searching to finally get windows vista sp1 to install on a laptop I was working on.  Below are the steps I did to resolve this PITA issue. 🙂  I hope this helps someone out there.

1. Uninstall any anti virus program you have installed.

2. Click on start -> run and type in msconfig –  Then select the diagnostic startup option. Reboot computer.

3. Run the Readiness tool.  You can download it from here http://www.microsoft.com/downloads/en/details.aspx?FamilyID=0435684b-8d12-4028-9cb0-b2903257f1fd&displaylang=en

4. Click on start ->run and type in cmd – Then in the command box that opens up type cd \ and then type sfc /scannow

5. After the scan runs (may take awhile) then type in takeown /F %windir%\winsxs\backup /r /d y

then type in cacls %windir%\winsxs\backup /g administrators:f

then type exit

6. Now go to http://technet.microsoft.com/en-us/windows/bb738089 and download windows vista sp1. Depending on the version of vista you have you’ll either download the 32 bit version (x86) or the 64 bit (x64) one.  Make sure you download the stand-alone versions. If you don’t know which version of vista you have it’s easy to find out.  Right click on my computer and choose properties.  You’ll find a line called “system type” and it will say 32 or 64 bit operation system.

7. Now run vista sp1 that you downloaded.  This could take an hour to install so be patient.

8. Once it’s installed and you have rebooted and everything is working now click  on start -> run and type in msconfig.  Now select “normal startup” and reboot your computer. 

9. Now that you have your computer updated with sp1 now would be a good time to get all the other windows updates you need.  So click on start go to control panel and select windows update. click on check for updates and install any updates it finds.  You may have to restart and do this process several times but keep doing it till you get a message saying there are no updates available.

10. Now that you have a fully updated computer and latest service packs you need to install your anti virus program back on.  DONE!

I know it seems like a lot of things to do and will take sometime (the one i worked on took like 4 hours) but you’ll have an updated windows vista computer and will have peace of mind knowing you have all the security updates needed. If you have any problems feel free to leave a comment and i’ll do my best to help.  Good luck!