Scared of "History of System Information" data results

I would like to ask you guys this kinda scary thought I've been having lately. Usually when I format Dave here, clearing out every bit of data in him (I think I do so) & re-installing Windows XP something weird happens.

Whenever I check the data on System Information after several days after installation & view system history the results would state that nothing has changed in my system's settings & yet when I view each category Hardware resources, Components & bsoftware Environment, everything says changed. Things like starting address, names of some .DLL & ACM Files get changed as well as manufacturer name & component versions of things change. What scares me is this:

Desktop.ini - Property "User" changed from "DEFAULT" to "All Users" - startup programs
Desktop.ini - Property "Location" changed from "Start up" to "Common Start up" - startup programs
Desktop.ini - Property "User" changed from "NT.AUTHORITY\SYSTEM" to ".DEFAULT" - startup programs
Desktop.ini - Property "USER" changed from (my PC's registered name) to "NT.AUTHORITY\SYSTEM" - startup programs

But everything in "Current System information" is still the same as it was. Is this thing normal?

Not related, I hope is another weird thing, sometimes, that thing that loads up with AVG 8.0's user interface, that notification thing that you can hide, changes what it usually say, the white background thing that says:

"Did you know?
The number of poisoned web sites is increasing. 1 in 1000 web pages are infected with malicious drive-by downloads (source IDG News).
With the new AVG 8.0 you can search and surf the Internet safely."

Changes to a pink one that says "Get complete protection with AVG Internet Security version", when ever the first issue I mentioned occurs.

Should I worry about these?

 

So it's nothing then, thanks.

Anyway, can you give a simple explanation in the form of an analogy as to what that whole changes thing is about so I can atleast understand what Windows is doing? Man I'm really strung on the fear of viruses or crackers. But the thing is, I really don't have anything really important in Dave anyway because I backup things immediately.