Microsoft → Re: Why is it bad to reboot a Windows PC?

It is true that a "hard" shutdown is BAD for a computer, like others mentioned a power loss or using the power button to turn the computer off.

However a regular shut down using the OS to turn the PC off is not only healthy for the PC, it allows security and other needed patches to be applied, it also saves electricity and prevently unnecessary wear on mechanical components like the HDD, fans, and other mechanics parts, also even though the PC is being cooled by fans there is still constant source of heat being applid to the chips like the processor, and this can still if left running constantly degrade the thermal paste quicker than if you turn the unit off when not in use.

I have an 11 year old HP Pavilion 7955 that STILL sees daily use 12 hours a day and it has ALWAYS been turned off from 12 am until 12 pm, it still functions PERFECTLY.

I have a 866 Mhz Pentium III system that has pretty much been powered up since I got it (used) in 2002, and it still functions perfectly.