ORIGINAL: Deadeye

F8 is the magic key to get into the safe mode menu options, not F5 (just tap F8 every second upon boot up). It is a Windows function, not a Dell or any other manufacturer function. A BIOS update will do you no good, and could make things worse. More than likely you are experiencing a faulty hard drive. When you get your hard drive connected to the device to transfer files, do the following:
1) find out the drive letter it is (I'll use F for my example)
2) go to Start>Run and type in cmd and click OK
3) once the command prompt is open, type F:
4) type chkdsk /f /r
5) when it asks you if you want to dismount the drive, type y
6) let checkdisk run, and post back the results. If you have any kb in bad sectors, transfer your files ASAP

If you 0 kb in bad sectors, put the drive back in the laptop, and try booting up again. Most times this works.