The Problem:- My computer starts up okay with the, then the windows XP logo, then the blue "welcome" logo, but then only wallpaper appears.There is no desktop icon,no taskbar.
Resolution:- Try to determine whether a damaged or incompatible driver is the cause of this behavior. To do this, start Windows XP in Safe mode, and then use the clean boot troubleshooting method to determine whether a specific driver or file is causing this issue.
How to perform advanced clean-boot troubleshooting in Windows XP
Other options to resolve this issue:-
Perform a System Restore
Create a New Use Account
Perform a repair install
315341 How to Perform an In-Place Upgrade (Reinstallation) of Windows XP