I had a WinXP PC from around 2004 that died some years back. I now am using a Win7 PC but the HDD is getting full. I salvaged my XP system's HDD and would like to add it to my current Win7 computer, but I'm not sure how to do this or if it would even work. Is there going to be a conflict of my computer not knowing whether to boot up using 7 or XP, or possibly even trying to do both? I don't want to wipe the XP's HDD because there are old files on there I'd still like to have, even though I don't need the OS anymore. Any guides or videos you could point me to to explain how to install a HDD with an obsolete OS to a newer PC without problems?