Run spyware and anti virus.
Then run checkdisk.
Load into safemode with networking. Is problem there?
run msconfig, uncheck all services, and process. See if that does it.
boo, with all the different problems you have had with this PC I would either reformat and reinstall or take it back all together and request a new one.
what do you mean, you can't do anything on start. The programs that load at startup are for enhancement to the OS and programs that you can run later. Nothing more...
leave the services alone at first and see where you get... I guess I can see where that would go...