I'm trying to compact my registry with Registry Mechanic, but having a problem doing it. I've scanned my registry and Registry Mechanic says I'm wasting 16% of space, so I ordered the program to compact it , and then it said that my PC would have to restart to finish compacting. However, I did that, scanned again and it still says I'm wasting the same amount of space! Does anyone know why this doesn't seem to work?

I have no idea, but the registry really doesn't take up much space at all. (check the size of the %systemroot%\system32\config folder to see what I mean.) It's probably not worth stressing over.

I have to agree with spike. Unless you have a miniscule hard drive, compressing the registry is a waste of time. If you want to make your primary hard drive efficient, move your temporary and internet files to a second partition or hard drive.

Then optimize all.

I managed to compact it with WinASO Registry Optimizer, another favourite of mine and my PC started up twice as quick. I wondered why it got so slow after time. I'd now even go as far to say that defragging my hard drive wasn't nearly as effective as defragging this registry. Certainly, as far as startup times are concerned. Thanks again guys!