When I switch on my computer, there jumps out a window saying something about the svhost.exe has error and the process has to be terminated.

Then, the system lags for a few seconds and the XP environment then goes out and turns into the old one.

Why does this happen? How can I solve it ?

Reinstalling WinXP should fix the problem. You can reinstal Windows without formatting by botting from the WinXP CD.

 

Chose Instal from the CD. Then when it finds your current version of Windows select Repair. Do it in that order, do not select Repair on the first screen.

 

By "turns into the old one" do you mean it goes back to default? Or what it should be?

 

NB: If you reinstal WinXP you will need to re-download all Windows updates and you will lose your Theme (default desktop background, screensaver etc.), but that is all. All programs will still work.

svchost.exe is a valid windows process; it is a program that hosts services. There are usually several instances of it, running different services. svhost.exe is a virus or something trying to trick you by using a similar name. Or maybe you just mistyped it.

the old version refers to the environment that the old windows give.

the window nt , 98