I was using diskmaster with WinUAE last night on my Win7 Toshiba Satellite, and just for kicks, I started to poke around DH4: which is your windows "partition". Disturbingly, I started to run across programs and demos that I thought I had erased a while ago. 8( WTH! Are you telling me, that this "modern" operating system, and I use that term loosely, if you tell it to un-install a program, that it leaves all sorts of leftover crap?
I know that nothing ever gets really and truly "erased" from a harddrive without it physically being destroyed, but, this is rediculous! Geez. If I didn't need this digitizing program, I would have happily ditched Windows.
Yeah, a lot of stuff doesn't get uninstalled. Usually you have files and folders left behind and settings still there. Not to mention the registry which is a whole nother game.
If you go to C:\Program Files\ you will usually find left over folders of long gone programs.
The other one is C:\Program Files\Common Files folder. Look in there and search around in the shared folders in there and you will find stuff probably from old programs (Norton will have like 5 even after it is uninstalled.)
C:\Documents and Settings\... (C:\Users\.... in Win7) and the tons of folders in there (it's just a damn maze) there will be tons of stuff in there. Check adobe folders I have found a single 1GB left over file in the Adobe Reader folder in many systems. If you check the folder sizes and work your way down you will find huge amounts of garbage.
Then there are other places things are left behind like,
C:\Windows\
C:\Windows\System32\
C:\Windows\System32\drivers\
It hard to know what is left over and can be deleted in these folders though. Norton programs for example leave tons of stuff in those folders as well. Most of them start with Sym or you can right click on each file and it will tell you if it is a Symantec file. You can delete these.
It's pretty ridiculous that all that crap is left behind. That's why these days I try to find "Portable Apps" of software I have purchased. They work like Amiga programs. Just run everything out of a single folder.
Then you can reformat and reinstall Windows when you need and you don't have to reinstall all your Apps.