Blank Screen during startup

I have a Gateway G6-450 Pentium II computer. About a month ago when I start up my computer, it starts fine and then goes to a blank screen with a hourglass. I can not move the hourglass or get off the blank screen. This lasts about two minutes. I can not figure out why this happens and what I can do about it. Any suggestions? I have downloaded programs but can not figure out if one of these is the problem.