XP Home Sudden Reboot

[cash_site]

Have you you done complete virus and anti-spyware scan of the computer.. also, have you updated to SP2 or at least fully patched with Hotfix updates??

That should take care of that aspect, some other members will follow up with Hardware related troubleshooting

[Shortie]

all that is done

still same prob

[godfather555]

First you need to check out what has really happened to your system.
Go to:
Control Panel >> Administrative Tools >> Event Viewer
This shows the log of the system, you need to find your problem i think it will most likely be in the "System" look for "Save Dump" in the source column.
Double click on that and see what the error was most likely it wont say much just numbers, still post them here it will also provide you with a mini dump (which is a pain in the .... to deal with). You can do a search on google with the numbers event viewer provides you.
Other then that i think this mainly a bios hardware problem - try reinstalling the drivers for your dvdrom

Hope this helps,

Tyson