I had this same problem with an HP/windows machine. In my case I had all of my family's info,taxes pictures, movies (it was media host) etc. After replacing the hard disk and attempting to use the HP recovery tools which to my shock would only let one recover from back ups from removable media (floppies!) not CD-r or in my case an external disk.
After smashing the computer to bits in the back yard with my son (excellent father son bonding over a irrational response to failure) we went to the mall and bought a laptop for him and I bought 2 refurbished MacBooks for my wife & I. My son installed Linux on his laptop.
I've replaced the hard drive twice in my MB. Once due to a noise that sounded weird and one to add capacity. Both the upgrades and data restoration were simple and loss free.
My son has been using that same laptop with Linux for more than 5 years. Same with the two MacBooks.
I always wondered what the issue was with that HP Media Center as it had eaten up so much time in diagnosis and rebuilding data from other sources. Many weekends and late nights. A friend of mine who is a DataCenter engineer & one of the best network architects I know had a similar problem on one of his PCs (a Dell) and narrowed it down to a driver update pushed out by Microsoft as a Windows Update however, it required a BIOS update that needed to be installed prior to the Windows Update.
CB - it's been years without worrying about downtime or data loss. I would offer that if your going to spend good money on a new machine - please look at Apple & other Linux OS options. You may never have to spend the weekend worrying about your computer.
Best of luck!,