I get the error "No Operating System Found" at bootupand the pc simply
resets and then the above error comes up again.

I have tried to re-image this PC but the imaging process complete's to early and then the pc reboots and the error is back. I have replaced the HDD ... no change.

Could this be due to the motherboard, as the first time this error cam up there was a working WIN XP image installed.

Any info welcome

I had this error on a friends PC recently and turned out it was bad sectors on the hard disk...you have replaced yours though, so...

First I would check that you battery on the motherboard is OK, save some boot order settings or something in the BIOS and check that the settings are saving. Also check in the BIOS that your hard disk is being recognised correctly.

Yep .. the HDD has been replaced.
But I have yet to check the battery and bios settings.
I will do and that now !

Okay problem found .. the bios required to be flash updated
I have the HDD in another PC and it reimaged fine. Thanks for the help.