I have built PCs in the past, but always using virgin HDDs. I'm helping a friend build a system, but he is wanting to take his HDD from his old system and put it in the new homebuilt PC. The HDD already has Win7 on it and was in an HP factory-built system. Since the new homebuilt system is using a different motherboard and BIOS (ASRock), will this affect the HDD at all? Should the HDD be wiped before it is installed in the new PC, or is it simply a matter of plugging it into the new system? If he plugs it in to the new system, will the OS run as business-as-usual, and ignore the fact that it's in a new PC? I'm wondering if a new BIOS will conflict with what's already on the HDD.
hello... just plug it in and try it... it will boot to Windows 7 or it won't... I've seen that due to more generic drivers in Windows 7... But this is a good time for a fresh install using his existing license from the OLD machine... it IS transferable if you type in the sticker code... and call to activate within 30days... I would suggest downloading the proper ISO Windows version file... Use windows ISO to USB/DVD utility... and do a USB install.
As said, most likely it's an OEM license and won't work with the new hardware.
HOWEVER... I have heard of people who have called MS support to report that that their OS doesn't work in their system. The support reps say that it doesn't work because the OEM is tied to the hardware. The caller then says that the MOBO and all were replaced due to hardware failure. Sometimes the MS reps will allow the OEM license to be reused in that case.
Assuming that he'll be able to reuse the license (big assumption), have your friend copy down his product key. He'll want to wipe and do a fresh install for best performance - he can then reenter the OEM key and see if it works and/or try the above. If he has to buy a new key, he'll have to reinstall in any case. Make sure all the data is backed up before a reinstall, obviously.
You can always just plug it in and see what happens. BUT, prepare for the worst first. Save all data, music, pictures, etc, anything you do not want to lose to an external drive first before removing the drive from the current computer.
Rule of thumb, new computer requires a new Windows install you cannot simply move a hard drive with a Windows installation from one PC to another. Some folks can get the old install to work, but take my word, it can be complicated and it will never be completely right, will always be buggy. Been there done it many, many, many times.