Why does it say that it it cannot find the hard drive or boot device.
The most common cause for this error message is that most computers are setup to look at a removable media drive, such as a floppy or CD/DVD drive first, before looking at the hard drive. If your hard drive gets corrupted, this allows you to put a boot disk in the removable media drive and boot from it instead of from the Hard Drive.
If you accidentally leave a disk in a removable media drive that's in the "boot sequence," the computer will tell you that there's no boot information on the first such drive it encounters that has a disk in place, and will stop and wait for you to either provide a bootable disk in that drive, or remove the disk that's in the drive so it can proceed to the hard drive. The error message is partly at the option of the OEM maker, and Dell may have modified it; so it's possible it won't tell you which drive it's looking at.
If Dell has substituted an ambiguous message for the standard Mickeysoft one, it may look like you've lost your hard drive, when all your really need to do is kick that CD (or floppy or IOmega Disk) out of the slot.
If your boot is actually getting to the hard drive, and isn't finding the proper startup files, then the three likely causes are a setup error, or a malware invasion, or a failing hard drive.
was given instructions on how to uninstall and re-install the hard drive can have a couple of meanings. I suspect that your were not told to open up the computer and remove the hard drive(?) although on some chat boards you might get that advice.
What they probably told you to do was to go to Control Panel, Device Manager, and "uninstall" the driver for the hard drive. This sometimes helps if a driver or one of the associated files is corrupted, since the PnP (Plug and Play) process when you reboot will find the hard drive as an "uninstalled hardware device" and will reinstall whatever the system thinks is needed to make it work. The suggestion that you try this does not mean that your hard drive is bad. It means that the software that talks to your hard drive may be messed up, so you re-load the software.
If your computer has booted okay since you "tested" it, I wouldn't bother unless/until you get some additional indication that it might help. You can keep those instructions just in case more problems come up.
If you really suspect a problem with your hard drive, the first thing you need to do is determine what it is. You should have, or be able to get from Dell, a complete itemized list of everything that came with your computer. (I won't guarantee anything "you should be able to get from Dell," but ...) Once you know the maker and model number of the hard drive, you go to the drive manufacturer's website, look in their support section, and find a diagnostic program that you can download to test your hard drive.
Be advised that most such diagnostic programs include some tests you can safely run without losing data on the hard drive, and also some tests that will ERASE EVERYTHING on it. Be very careful which ones you run. Most "failing" drives can be detected using the non-destructive tests. You'll have to decide for yourself whether there's sufficient concern to merit getting and running hard drive diagnostics. But backup your data anyway...
last night I had to click on "off" about 3 times???
Do we assume you're using the standard "Start|Turn Off Computer | Turn Off" procedure when you shut down your computer? Some computers will shut down using a hardware button on the computer, and doing it using the hardware button will cause problems, especially with subsequent boot and shutdown.