I found that this actually seems to be a reoccuring problem with Dells on here...
I have a Dell, it's pretty new, a little less than 4 months old, (but about 3 weeks past its warrenty expiration, go fig) it was running fine until about a week ago when I turned it on and there was a double beep that usually doesn't happen, followed by the "Primary drive 0 not found, yadda yadda press F1 to continue, F2 for setup" bit appeared. Pressing F1 didn't do much more than make the computer beep at me and tell me to press F1 again, so I went into setup.
I went into boot sequence and was given two checkmarked options of "Boot from Hard disk (not specified) and Boot from CD". I have a feeling I should be able to change that not specified to my primary drive but I've yet to see a way to go about doing that. Anyways, I've found that just changing any setting then changing it back to what it originally was (ie.e changing auto to off and back to auto, or un checking then rechecking one of the options) then hitting esc and saving the changes causes it to boot up fine and run properly until the next time it decides not to boot properly (about every other time I try to turn it on). I can only hope the drive is not dying since it's so new and seems to run fine once it's been pointlessly messed with.
Any suggestions or info would be very welcomed, thanks.