Following your chain of thought and events, coupled with the current dilemma, I suggest that the ribbon may not have been the problem the whole while. My best guess right now is the hard drive itself. If your grandfather has any data on that drive that is important, then your #1 priority needs to be backing up the data to another drive or storage medium.
Here's what I might try doing:
[OL][LI]If you have a spare hard drive, and can connect it somewhere, do so.[/LI]
[LI]Download an Ubuntu Linux CD from www.ubuntu.com[/LI]
[LI]Burn that disk image to a CD. Download ImgBurn from
if you need an app for that.[/LI]
[LI]Boot the ailing PC from the Ubuntu Disk, and tell Ubuntu you want to try without installing... That's the Live CD Version. Or if it doesn't ask what to do, you can select "Install or Run"[/LI]
[LI]Once at the desktop, see if you can browse to and find your grandfather's files, then copy those files to the spare hard drive (I'd look for Internet Favorites/Bookmarks, My Documents (or Documents), pictures, etc. If your grandfather had a business, make sure what programs he used for the business, and be sure you know what files to look for there. I was shocked just yesterday afternoon when I had to tell someone how to tell their OEM PC Tech Support person HOW to find Quickbooks data files. I kid you not... as popular as that program is for small businesses, and the tech support was clueless as to how to find the files... and it was more to that story, I won't delve into.[/LI][/OL]
Then once you've gotten all the data backed up if possible, you can move to testing to be sure of what the issue is. A bad hard drive can cause a system to just freeze up like that, and to refuse to boot.
Of course the easiest way to eliminate the hard drive as the cause of the system problems is to simply unplug it, and see how the computer acts without it. If it goes through BIOS fine, and just gets to a screen saying no boot system found or something, then it's very likely that the hard drive is the problem... or the connection/cable could still be the issue, but I'd go with the hard drive at this point.
If you want to scan the system to see if it's the physical hard drive, or just something with the Windows install, or whatever else, you can download the
UltimateBootCD and try the various apps on there for testing.
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"If to err is human, then I must be some kind of human!" -Me