I didn't "read" the question, it's not an issue of installing a program but a question of keping track of the registry when you alter your setting.
My first reply to this question is a great way of keeping track of a new install.Shawn
Nice and functional!
If you don't have a clou in whitch key to look in and diskspace is not an issue, but Your time is, why not export the total registry:
1) Close ALL open windows (quiet your machine)
2) Go Start->Run "regedit"
3) Hi-lite My Computer
4) Select Registry->Export Registry File... from the menu
5) Go File_name: c:\Before (the extention will default to .reg)
6) Make your change ( ie set your pagefile size or whatever )
7) Set focus to regedit again and hit F5
8) Hi-lite My Computer
9) Select Registry->Export Registry File... from the menu
10) Go File_name: c:\After
11) Pull-up a dos command window
12) Enter: FC Before.reg After.reg >Diff.reg
13) notepad Diff.reg and look for relevant changes
14 ) Delete C:\Before.reg and C:\After.reg