Old computers die, they don't just fade away, and if they don't demand constant attention on the way out their replacement requires tender loving care before they are ready to step up and do their job. My six year old desktop, Asmodeus, has been plagued by random crashes for several years. I sacrificed to it's appetite for components by installing a new video card and power supply at a cost of over $100 each before deciding it was never going to be reliable long term again. Which of course means replacement.
I believe that Microsoft and computer manufacturers conspire to make the replacement of a computer only slightly less stressful than water boarding. Having been in IT for the last 30 years I have always backed up my computers obsessively. Not only to external hard drives, but by cloning to a second HD in the computer itself. Now Asmodeus refuses to run consistently even on the clone so replacement is the only option. The problem is that you can only back up your data files. All your applications and peripheral hardware have to be reinstalled.
Find all those DVDs and CDs with software you bought. Find the ones with your printer/scanner/midi and other drivers. Now sit in front of the new computer for hours babysitting the installs. Oops here's one that won't register because you already have it on the old machine - Oh boy! Now you get to sit on hold while you wait for customer support to grill you like a criminal. Finally got all that software installed and now you get to try to install the software that you originally installed by way of downloads. Now where did I put the product keys for those? Inevitably there are some you pay for a second time because you can't find the keys and have to have them. Computer roulette = trying to guess which program won't run on the version of Windows® on the new machine because you can't buy a machine with the old version any longer.