Why do computers grow slower with time?

Especially Dell's... Slowdown despite constant maintenance with adaware, spybot, security task manager, defrag.

I fear a conspiracy by Dell and other manufacturers to force people to buy replacement computers as current PCs become unuseable.

Why do computers grow slower with time?free antivirus download

A combination of more complex programs installed, messy installations in the windows registry, less efficient memory allocation, and more start-up programs. Improper shutdown can complicate/corrupt the registry, or damage the hard drive (bye bye to all of your important files).

Increase RAM, clean the registry, avoid free programs which tend to really mess up your registry, stop programs from running in the background, remove programs from the automatic start-up directory, and shutdown Windows properly every time.

Why do computers grow slower with time?internet security

The best thing to do is to back everythink up you want to keep and reinstall windows with the recovery disk. Your registry is filled with to much junk. Most computer geeks do a reformat and reinstall at least once a year.
I think they might just get a little older and worn down as it grows older, but I also think that the new fast computers make the old ones look slow also.
computers get slower because with time you put more and more programs in it and that slows it down
I was recently doing alot of research on this and it's because of all the changes made once you start using it. You would be surprised what is hiding in your computer. Check out CCleaner. I just did it and freed up over 600 MB by getting of rid hundreds of things I dont need or use.
For one over time the programs are getting more complex thus more calculations, also the more programs you add to the system the slower it will get.-- that's just been my experience
I doubt that Dell and the other big brand name PC makers have a conspiracy in this regard (In other ways, likely, but not this way.) ;)