Tried to install vista SP2 from a disk and after the computer would not reboot. OS is Vista business with SP1 installed.
I know the disk is good have installed it on other computers. Any solutions!!!! OjasIf you have Vista DVD...

http://www.vistax64.com/tutorials/88236-repair-install-vista.html

If you don't have Vista DVD...

1. Create Vista Recovery DISC.

Option 1:
http://www.c4consulting.com.au/soluctions/vista/VISTA%20SOLUCTIONS.htm

Option 2:
Download Vista Recovery Disc iso image: http://neosmart.net/blog/2008/windows-vista-recovery-disc-download/
Burn it to CD, or DVD: http://neosmart.net/wiki/display/G/Burning+ISO+Images+to+a+CD+or+DVD

2. Boot from created disk.
At first screen click on Repair your computer:

This will bring you to a new screen where the repair process will look for all Windows Vista installations on your computer. When done you will be presented with the System Recovery Options dialog box:

After this, it will PRESENT you with a list of options including startup repair, system restore and command prompt:

Try System Restore, first.
If that doesn't work, try Startup Repair.est way is to get hold of the Vista SP2 integrated . iso and clean install.

You can save the existing data into a folder called Windows.old.
To do that , do not format the partition you wish to install to - just click on it and you will get that option.

Otherwise, you can try BOOTING to Safe Mode and select Last known Good Configuration.

Or boot the Vista dvd to sytem recovery options and system restore to before the problem started.

Or Boot the Vista dvd to the system recovery options command prompt and replace the REGISTRY manually.