also could you press F8 while starting up and when the options appear select "desable automatic restart to protect system files" (or something like that) and press enter
also when you have done that could you unplug all usb devices, printers ect. (basically anything not needed for your computer to run) and see if that prevents the restarts
it could be possable that the cleanup could have upset your systems configuration
i have attached 2 tools which might help
first could you try running shutdown logger (in safemode) and post the logfile it will on your desktop
next could you try starting up in normal mode your computer restarts and post the log it creates (it may allow you to start in normal mode to update)