My DELL OPTIPLEX 980 desktop is booting directly into safe mode no matter what I try?

SOURCE: Dell 4500S Desktop doesn't boot Windows

Sounds like a ram problem.

SOURCE: How to start in safe mode Dell Optiplex GX 150

Is it booting to normal mode?

If it is booting to normal mode, click start - run and type msconfig.
Click on Boot.ini tab and Check Safeboot. Click Apply and Close or OK. It will restart the computer to safe mode. Remember to uncheck Safeboot to make the computer to boot in normal mode again.

SOURCE: dell optiplex 760 won't go into safe mode

It sounds as though your PF keys are disabled by the BIOS settings. Try this:
Upon cold start or reboot get to the BIOS setup. You may have to press F2 or delete, or whatever key the first POST messages instruct you to use. Different BIOS manufacturers use different keys, and you have to be quick to interrupt the boot process using the correct key. If you fail to determine what key it is, reboot once again, until you see/read what key does the job.
Next, once you're into the setup screens, look for a section where you can set/deny access to the F8, F9, F10 etc keys during the boot process.
Make sure you ENABLE them, following the instructions on what keys to use to set/reset these choices. Make sure you SAVE AND EXIT.
On the next reboot, upon the disappearance of all POST messages, make sure you press the F8 key repeatedly until you see your OS boot options menu, among which you'll find Safe Mode.
Good luck!

SOURCE: Will pass bios but then will not load windows

step 1. open up the case and locate your hard drive
step 2. carefully remove the cables and power to the hard drive and remove it
step 3. goto your local office depot, staples, walmart or radio shack and buy a nice new hard drive somewhere around 250 gigs should be plenty for you,
step 4. now that yopu have a nice new hard drive put it in the spot where your old hard drive was in the conputer and plug both cables back into the new hard drive, after this is done put your case back on and start the computer up with your windows cd in the cd rom drive and reinstall windows. :) hope this helps

SOURCE: Dell latitude d630 won't boot up.

Can you boot in a Safe Mode with no problem? If you can try to use System Restore to return Laptop to previous state. Go Start----->All Programs------>Accessories----->System Tools-----> System Restore It's easy to use and it may return your system to time when it worked properly. Good Luck!