How often a reinstallation is needed does depend on how fast the computers are and how much they are used. <...>
@nick: I would venture that "used" should be taken as "abused"... not in a mean way, mind you. But if one abuses a Windows PC by running lots of non-polished applications (alpha, beta, homebrew, poor commercial apps.) then the install/uninstall process may simply not be perfected; which is to say, trash gets left in the registry and is often "version centric" which means with each new test version comes a new branch of the software tree! This is nasty business. Even Microsoft is not all that good at working miracles on the uninstall of programs... often Technet released software and public/developer previews will play havoc with the registry.
Using a PC 7x24 will have absolutely no affect on the registry size, however, using a Windows PC with lots of software which undergoes install/uninstall will likely create issues... perhaps in stability or perceived operating speed. RAM goes a long way to combating this issue, but ultimately most folks resort to simply reinstalling the OS.
A dated article but still relevant:
registry-junk-a-windows-fact-of-life.aspx Some may recognize Mark as one of the authors of the old
SysInternals set of Windows utilities.
- Ray
PS: My dual-processor HP that I use for video DVD and digital camera art is 5 years old and has NEVER been connected to the Intranet... it is on a private TCP/IP, non-DHCP LAN segment so the router blocks access! This machine has never had a single Microsoft Update to the installed XP. While I have installed all manner of software: SCSI film scanners, Canon flatbed, Nikon/Canon/Sony video and editing software... the box runs just as fresh as it did on day 1. I have replaced some hardware, but I never uninstalled the old drivers... simply no reason to do so. This is an example of Extreme Windows Computing where the value of the software and function that the software performs outweighs the price of the hardware. I have two such machines that are workhorses that get serious usage but are dedicated... to keep costs reasonable, I buy refurb manufacturer hardware (big discount.)
Windows is a complex piece of software and is not perfect. It is good, but not great (well, not super-great anyway.) For a commodity product, MS has done pretty well, however.