I'm new to the forum and I need help. I have an old Dell Optiplex GX150. When I turn on the machine the Dell logo appears and posts but Windows won't boot up. After a minute or so the logo goes off and I get the following message:"Press F1 to try again or F2 to enter setup. I've tried F1 to no avail and when I go to F2 there doesn't seem to be any help there. What next?

Well could be your system has crashed or problem with the hdisk. To be sure, try getting hold of a Linux LiveCD and make your system boot from that cd, if it loads ok then hdisk is ok, problem could be with your windows setup

how about reinstalling the system?