Could be various reasons for the problem, such as a corrupted icon cache, a virus, or even some kind of spyware.
Can you use a keyboard shortcut to access My Computer? (Windows Key+E) Then you can delete the hidden IconCache.db file found at C:\DOCUMENTS AND SETTINGS\ USERNAME\LOCAL SETTINGS\APPLICATION DATA\IconCache.db (where USERNAME is your account name). This will force Windows to re-build the file.
no, i cannot use the windows key + E after start menu disappears....
btw, if i click really rapidly at the desktop, then cilck oncec on a icon, then start menu, then the "show hidden icons" button on the bottom right corner of screen, then the startmenu... it sometimes works
Maybe the simplest way to correct the problem would be to just run a repair on the OS to replace any corrupted files, although you'd have to reinstall all the hotfixes afterwards and/or SP1 from Windows Update, depending on the age of your OS CD, which may or may not be slipstreamed. (Myself, I prefer just the hotfixes and I normally avoid installing SP1, due to unusual errors I have seen on several systems.) Or you could check to see if <A HREF="http://www.microsoft.com/windowsxp/pro/using/itpro/mana..." target="_new">System Restore</A> is running, and then roll back the OS to a point that precedes the date when the problem started - - <A HREF="http://www.michaelstevenstech.com/XPrepairinstall.htm" target="_new">How to Perform a Windows XP Repair Install</A>.