PC Problems - HELP!!!

Hi.
Couple of problems:

Whenever I log on to my PC, it displays a message saying that one of the registry entries was missing and had to be recovered from a previous version. I don't understand what this means and how to sort the problem out.
Also sometimes when I log onto my PC sometimes the theme has changed from Windows XP to windows classic (although in the display properties simply shows as Windows XP (modified) and i cannot change this to Windows XP theme.
Then the other day when i logged on, i went into outlook 2003 (where i had everything set up) and the mail accounts had all dissappeared. . . I don't know why. . . yet my mail remained in the folders i had previously put them in.

Is there any way to sort these problems out? Are they all related? I don't understand it! Help!

Also i get a message sometimes saying something like "memory at reference ........... could not be.........
what does this mean? How can i fix it?

Please help me! I'm not sure what to do!

Regards
Tim

 

You have windows xp, do a system restore, go back to a later date. See if that works. Let me know.

 

If you could get the exact error and write it down then post it this would be a great help towards fixing the problem?

 

I tried the system restore, and the same thing keeps happening. . .

Also with regards to the actual message, do you mean the memory one?

Thank you both for replying!

Warmest Regards
Tim

 

Actually I really mean all of them because trying to fix a computer with out the error messages is just guessing at the fix.

 

This is the memory one. This is only occasionally. . .

The Registry one, thats comes up every log on is:

"One of the files containing the system's Registry data had to be recovered by use of a log or alternate copy. The recovery was successful."

Regards
Tim