Problem with System Restore on Win 10

No current, recent, backups on external media, correct?
On another computer, create a USB or DVD boot of whatever backup / restore /clone utility you believe will work best for you, attach any affordable external device (probably a 1TB+ HD is best), boot that b/r/c utility, make backups of your Data folders and files first. Whether or not to backup your busted OS, let's ask the others in here. What I have done is back up the collection of folders containing the icons, shortcuts, etc. of all 3rd party installs. Such will give you a road-map should re-installs be necessary.

P.S. I'm fairly new to Windows 10. Tried to get into Safe Mode but all the instructions I found show Windows already loaded. ??

By default you can only get to Safe Mode if you can at least boot to a logon screen. Forget F8 in Win 10.
(Note for future: It is possible to add Safe Mode as an OS choice in you boot manager- see the Tutorial section for that).

Help! I don't want to lose all the data and programs on this PC.

Data is comparatively easy to recover at this point, assuming no disk corruption, and assuming you have neither backups nor use disk imaging, as we constantly recommend. Disk imaging means you have way of recovering to a previous good working state quickly and easily and hopefully without technical help. E.g. Macrium Reflect (free). Also acts as a full backup; even useful if your disk fails.

One way-you can boot your PC from a boot disk e.g. Kyhi's available from the top of the Software and Apps section here, and recover anything not backed up.

=====================================
Possibilities:
1. Boot from Kyhi's boot disk, run Macrium Reflect, and use its Fix Boot utility. If you are very very lucky, you might have some success.
2. Research 0xc000021a
E.g.
Windows 10 BSOD error 0xc000021a - Microsoft Community

A simple search yields many results.

If I may add something to dalchina's post:

- if you decide to boot from Kyhi's boot disk and run Macrium to fix boot, take 10 minutes and make image of your drive. If you later decide (or you can't fix the system) that you perform clean install (fresh copy of Windows), you can mount that old image and get any file left on your computer.

Users usually take care of their data files and forget about files on Desktop or other locations.

AndreTen, good catch about data stuff inside of Desktop folder and other places! Because I allow nothing but icons to sit in there, I forget to mention Desktop's contents.

sillycat41 said:

Tried to get into Safe Mode but all the instructions I found show Windows already loaded. ??

Maybe this will help
Check option three
Boot into Safe Mode on Windows 10 Windows 10 Tutorials

EDIT: Although there are more ways to accomplish getting into Safe Mode without normally signing into Windows here is what worked for me.
Adjust what shows up for you according to what your computer reports.
--- It might not work for you based on the condition your computer is in, but it's worth a try.
--- If you don't use the same install media I used, the solution might be different.

I used a Bootable USB Flash Drive per
Create Bootable USB Flash Drive to Install Windows 10 Windows 10 Tutorials
Upon booting up through the Bootable USB Flash Drive
Windows Setup screen: select Next
Windows Setup Install now screen: select Repair your computer
Troubleshoot
Command Prompt
Administrator X:\windows\System32\cmd.exe screen
--- X: \Sources>
Type bcdedit | find "osdevice"
--- Results reports osdevice partition=E:
Type cd e:
Type dir e:
--- You will see <DIR> Windows in the list
Type bcdedit
--- In Windows Boot Manager, the identifier is {bootmgr)
I did bcdedit /set {default} safeboot network
--- The operation succeeded successfully
I repeated the process a 2nd time but that did not succeed successfully.
--- Below that in the Windows Boot Loader, the identifier is {default}
--- Type bcdedit /set {default} safeboot network
--- The operation succeeded successfully
--- Why there is a difference in there I do not know process went well.
Exit out of command prompt
Choose Turn off your PC on the Choose an option screen
Remove the Bootable USB Flash Drive
Start the computer
Enter your password
You are in Safe Mode with Networking
When you want to boot back to normal startup, you can type msconfig in the search box
Select the Boot tab
Uncheck Safe Mode
Click on OK
Click on Restart

Good luck