ME startup problem

Hi all,
I'm having a bitch of a problem with ME and wonder if any of you have had the same experience.
On starting, I get a grey screen with a dialogue box saying that I need to restart my computer to finish installing hardware. If I do restart, it just comes back to the same screen; a bit like a recurring nightmare! What's more infuriating is the fact that I have not installed new hardware.
I have done the whole msconfig thing with a minimal startup increasing by increments to a full startup. No result but it did start clean for a few days. I got the problem again intermitently and have tried system restores which work once or twice and then it will not restore. I have tried a registry cleaner which got rid of 157 useless entries. I regularly run updated spybot and antivir.
Now I am at the stage where I get that sodding grey screen at each sartup. If I restart in safe mode and then run "scanreg /restore", I get a clean restart and can use the PC until I have to start again.
If anyone has had this problem I would love to know how you conquered the evil little s**t.
Thanks a lot,
Steve