Really need help, something wrong with Vista

OK, here’s the thing, this happened twice in one day. I format my HD 500GB SATA WD, fresh install Vista Ultimate x82, install all the programs I usually do, and all the drivers. Everything is working fine, and then after one restart I get this.
No massages no nothing, just that. I can run all the programs, go on line, but it’s like there’s no desktop, no slide bar, no start button. Can someone help me please, I don’t know what to do any more, spend the entire day installing and still I get this.
HELP!!!!
Answer #1
Start task manager and look for a process called explorer.exe .. and tell me if is there, if now try this: file>new task> (type) explorer.exe>enter
Answer #2
Thanks for a quick reply , I fixed the problem already, just typed in google and found the solution. I just needed to change the Shell path in regedit to explorer.exe and that was it.
So problem solved. Thanks anyway man!!!