i have installed win7 home premium on my hp 6730s 3 days ago. since yesterday it started shutting down and restarting itself sometimes even before windows completes to load; also some times there is a glitch on the screen before restarting; i am not getting any blue screen
i tried a lot of stuff like running only on battery, running from power supply only, cleaned for dust, checked all installed drivers, ran disk check from windows...it's really annoying
You should put in your Windows Installation disk and run startup repair to make sure that none of the files in your Windows Installation are corrupted.
Once you've done that you should download the Kaspersky rescue disk image and burn it to a CD. Boot from that CD and run a full virus scan of your computer. The symptoms you're experiencing may be the result of a virus or rootkit which the Rescue Disk should be able to find and destroy.