windows 7 boot error code 0141

I started having problems logging into windows a week ago. The system would stop at the Dell Logo and tell me to push F1 or F2. I would go to F2 exit  and it would allow me to log in.  Starting yesterday i could not get to windows, I would get a BOOT error code 0141 "No hard drive detected". I think i may have changed the booting sequence or other item in F2 trying to correct the problem. I need the correct booting sequence and setting in F2 for Windows 7. I also would like to find out how to correct the error code.  I can't log in on the computer in question Dell Inspiron 400 ZINO Desk Top. I am working now out of my laptop which has windows XP.  All help would be appreciated.

Thanks,