Windows keeps registry files from everything that happens on a pc, but it's not JUST Windows. When you install programs etc...many things get left behind and you can't clean everything as some become shared critical files, etc...A pc does in time get cluttered but whether or not you HAVE to reinstall every so often , isn't a rule. It really depends on what YOU do on your computer and how often. I do typically reinstall my system before the year is up. As mentioned, you can't get rid of everything and a reinstall is about the only way to actually do this without chancing further corruption by deleting needed files. If you keep the computer from getting a lot of junk to begin with , regular maintenence can keep it running fine as the pc i'm on right now, hasn't had a reinstall in 3 years. It's my wife's so I don't keep up the maintenence , she does, lol. But it does run fine with regular defrag, cleanup, etc...
So while the basis of this is TRUE, for sticklers as myself will reinstall as often as possible where people such as my wife simply don't care and do regular maintenence.
I was at a computer club meeting yesterday and there was one discussion about how Windows creates many files that over a relatvely short time significantly degrade the system's performance. One person there, taken by most present as being something of an expert, said yes it is a problem and that the only way to deal with it is to reformat the hard drive and reinstall Windows and everything else. He said it probably needs to be done once or twice a year.
Is this problem real? Is nuking and repaving the only way to deal with it?