Cannot open Windows xp completely

I can get a C prompt in Safe mode and when I run explorer.exe, I am able to to get start menu and all the programs and icons. However, if I reboot in safe mode, the icons do not come up and only the mouse arrow appear. When I do a normal reboot, the program starts to load windows xp and reaches the desktop image appears but the desktop does not open and there are no icons or start button. Can anyone help me out of this dilemma. Thanks. MMN