In the event after clearing the NVRAM you get an error regarding the diskette drive on boot up and you don't have a floppy drive then just go back into the BIOS Setup. Turn Off the option for the Diskette Drive and the error message will be gone on the next reboot. That option can be found in the Drives sub-menu. The reason this occurred was that clearing the NVRAM defaulted all your BIOS options back to their factory settings. On some models this defaulting will turn on the Diskette Controller even though there is no floppy drive in the system.
I would also recommend running the Dell Diagnostics on the system. An F1 - F2 boot up scenario can be an indication of a failing drive.
This just worked for me too! It's been driving me nuts. I have Dimension XPS (2004) and the battery on the motherboard died. So I got a new one and have had this problem for a few months. Finally did some searching and found this. Worked great.
The machine has been upgraded since I got it in 2004 with more memory, another hard drive and Windows 7. It's been a great machine and still does what I need.