I finally felt brave enough to try to understand what the registry was and does.
I looked for a primer on the net, and came up with the following link
it talks about registry files on the disk
system.dat and user.dat, i have located system.dat but cannot find user.dat, is that something which is not present in windows xp?
i looked in my windows folder and saw a number of other .dat fiels, are they all part or associated with the registry?