Sometimes I think my computer is bulemic and that I'm the enabler. I'm
forever cleaning the registry (Win XP Pro) and deleting so-called junk
files, using Iolo's System Mechanic utility to do both. Exactly how
important and effective is purging the registry of invalid values? I
remember reading somewhere that doing so is equivalent to sweeping one
parking place in a lot the size of Montana. True?

Hi nautico...

Since, most of the time, when the registry is accessed, it's accessed
by a very specific address, it isn't like the registry has to be 
searched in order to find them. In that case (which is the majority of
the time), the size of the registry is of little concern.

It can become a concern, however, as your registry approaches the 
maximum setting. To check the current size and alot more space, if
needed, follow the guidelines from this page on SmartComputing:

"If you are
 using WinXP, open the System Properties dialog box in the Control
 Panel (click Start, Settings, and Control Panel, then double-click
 the System icon). Click the Advanced tab, then click the Settings
 button under Performance. In the Performance Options area, click
 the Advanced tab then click the Change button in the Virtual Memory
 section. The Maximum Registry Size (MB) field is at the very bottom
 of the dialog box."
http://www.smartcomputing.com/techsupport/detail.aspx?guid=&ErrorID=25377


In summary, good housekeeping is generally a good thing, but if
you find you're getting obsessive about it, know that you can
afford to relax and ignore the clutter at times.

Since Iolo's System Mechanic is automated, it shouldn't take much
effort on your part to do the job, but if you'd like to run it 
once a month instead of every week, it won't hurt your system one
bit.

sublime1-ga

Thanks. I shall herewith refrain from such frequent registry purges.