After five years and a few months on the same machine (Athlon 64x2 6000+ under XP), I finally gave in and went for some shiny but expensive new hardware (i7 3770, 16 GB, 128 GB SSD, 1.5 TB HDD, GeForce 660 TI - what the doctor ordered and then some, a machine built to last the next five years).
This of course left me with the nice task of migrating an XP system to Windows 7 (Yes, 7. One of my reasons for upgrading now was to be sure to still get a real desktop OS for this thing, not a tablet OS) without losing anything. Thankfully, I had both my software and data in order and everything went quite smoothly, even all the Firefox passwords and settings, Thunderbird mail files with a complete record of my mail since the late 1990s and my various online Flash save-game states (If anyone ever needs some instructions on how to migrate any of this, I'm now an expert on it). So let's copy over those last few Gigs of data through the LAN and in the meantime set up the old box for the wife whose even older machine had just recently bitten the dust.
Click... click... that doesn't sound right. In fact, that sounds like a hard disk not doing what it's supposed to do. And here they come - various read errors on the system partition. Which means, better NOT crash the OS now because that machine won't ever come up again from this disk. Get those last bits of data, dump the registry (which thankfully still read fine) in case I need to transfer a software license key or some settings for a program whose setup files I can't find anymore.
How likely is it that you actually have a HD fail on you on the LAST time you actually need to boot it, at a time you're essentially already done recovering the data? I guess whichever greater being is responsible for computers was watching over me this time... no need to test my backups. Phew