XP won't boot "Reboot and Select proper Boot device" - bad boot record or HDD?
Recently I took a look at my girlfriend's PC as explorer crashed each time it was booted, even safe mode wouldn't work. I opted to re-install the OS from scratch. The only problem I had was that she needed some files backing up, so I had no option but to plug her HDD into a spare SATA bay I have in my own PC (80GB of data needed to be saved, I don't have an external HDD that big).
Anyhow, I backed up the files to a HDD I have in my computer and then re-installed Windows on her HDD in my own PC. I then put her data back onto the HDD. Everything worked fine in my PC, I was able to boot into Windows XP no problem. Please note I didn't install any drivers apart from any defaults the XP install detected and installed.
After putting the HDD (with the assumedly fixed XP install and recovered data) back into her PC I cannot get it to boot at all. I get the following error message:
Reboot and Select proper Boot device
or Insert Boot Media in selected Boot device and press a key
I have tried the following and keep getting the same message:
1. Checked BIOS and set it to default.
2. Removed the system battery to hard reset BIOS.
3. Performed a full repair on the XP install using an XP CD.
4. Executed several commands in recovery console: bootcfg, fixboot and fixmbr.
5. Used chkdsk, HDD appears to be fine.
6. Unlpugged everything, checked connections, etc.
I assumed it was some kind of driver issue from using my PC for the fresh install, but as repair nukes the Windows system files surely this is not the case.
Any ideas? All help is highly appreciated, pulling my hair out here. Thanks.