This is a new case for me, but all of those "look and feel" items, like the start button and quick launch, ect. are controlled by the file called explorer.exe(found in the default system folder: C:\WINDOWS\explorer.exe). This is normally running, which allows you access to all of those things mentoned above, but in your case, it abruptly stops.
...Check to see if the icons and such go away when you just sit there, and do nothing. If they do not dissapear, then try to find out what causes it to stop. Just click on a few things, like the start button, expand the icon tray, right click on the desktop, ect...and isolate where the problem is. If it closes only when you do something involving it, the you need to do fix step #2 below.
There can be many many reasons for it to stop. I will list a few:
1. Virus (probably not, and you have a virus blocker)
2. Unsafe modification of the explorer.exe file to gain a more personal look. ie. changing string vars. or changing the windows icon - causing it to crash when certain things are done involving explorer...
3. Explorer.exe could be having a conflict with another application and is being forced to stop running.
4...Other small things.
Various Fixes:
1. Simply press Ctrl-Alt-Del and File>Run...explorer.(If it cannot be found then try explorer.exe. Or search for the file, and put the whole path in the run box. If you cannot find explorer.exe then there is a big problem...
2. Find a windows xp site that has default backups of certain system files, find explorer.exe, download it, rename your explorer.exe to explorer.exe.old and place the new one in the folder the old one was in. Restart. See what happens, you can always revert back to the orriginal.
3. Start windows in a safe mode, (to determine if another app is causing it to close.) If all the icons go away and such, then you have a bad program that is conflicting with explorer and you should isolate it, and delete/disable it.
4. a) Learn the language of India.
b) Call your computers support hotline.
c) Post your question in http://www.in.answers.yahoo.com
Also, this could be a problem with your computers specs. It might not be able to run win xp safely and securely.
Any other specifics, just msg me.