So im trying to repair an old desktop PC and It has 16gb of ram (cannot remember the brand off the top of my head, but its just generic ram, nothing special) I7 Processor, and I just threw in an old 320gb seagate HDD that I pulled out of an old HP which was working as of 2 years ago when I decommissioned the tower ( it was a media center, but the ram and processor were just too old). When I put the hard drive in to the new pc Im planning on using for the same thing ( its a dell). It just goes into an infiniate boot cycle.. The Hard drive has windows xp on it and the original dell hard drive that went out had windows 7, not sure that makes a difference. Im not against booting into bios and wiping it, but just want to know what would cause it to cycle like that? The pc turns on and it goes to the dell screen then windows loading then back to the boot options screen.