One of my customers recently had the worst of all events happen to him - a hard drive crash. One morning his PC simply didn't power-up. There were no warning signs - this catastrophe came out of the blue.
I had a spare hard drive on hand and began the task of building a system as close to what he had as I could achieve. The main trouble was that he did not have much source media for the software which came pre-loaded on his PC. I was able to load Windows95B, Word, Netscape and AT&T Internet from the few existing cd's he did possess. His modem, video card, sound card and CD drivers were another story. Eventually, after much research, I was able to download them off the web sites of the manufacturers. He still lost a few applications as we now have no way to reload them. Fortunately his data was stored on separate floppies and was therefore not at risk.
The moral of the story is: make sure you have original media for the applications you have on your PC - floppies or cds. Many factory-loaded PC's come with a complete set of source cds or even a set of śrecovery cd's. However, many brand-name computers are being shipped with no media for the accompanying software. In those instances, the user will often find a śmake system disks' reminder window flashed at them as they boot their PC. This requires a large number of floppies which are then written to by special programs included on their PC. This gives the owner 2nd hand source media (my terminology). It is better than having no media and can save them a real headache should the worst happen to them. But this home-created 2nd hand media can also end up being unusable because they were not created error-free (through no fault of the owner who fed floppies into his drive in accordance with instructions on his screen).
How do you avoid being unable to restore your system and applications? When you purchase a PC from either a local company or a distant name-brand company - take time to ask about source or recovery media. This should be a criteria in choosing your new PC as much as performance and price.