With Windows 10 and computers now using UEFI instead of BIOS it now is different to get to system restore, safe mode and other start up options in Windows 10. Prior to Windows 10 all you had to do to get to these was press the F5 or F* button repetitively at boot (start) of the machine.
There are lots of suggestions of how to do this now in Windows 10 and some work, although requiring lots of attempts. The following is what I have found to be the easiest way, although it is still more complicated than prior.
If it is a desktop computer, boot or start the machine and then while it is booting pull the power cable disconnecting the electricity. Plug the cable back in and then repeat one or tow times. The third or fourth time when the circle that has the line going around it appears you will also get a message to Please Wait. Leave plugged in this time and it will come to a blue screen asking whether to continue starting Windows or go to advanced. Go to advanced (mouse and keyboard will work) and then you will have some repair options which may be where you want or do advanced again and it will give option for safe mode, etc and also an option for System Restore. These options appear when Windows decide s you are having problems booting.
On a laptop do the whole process with power cord unplugged and everywhere in process I said in above steps to pull power cord, remove the battery and reinsert. This way the machine loses all power the same as when power cord pulled in desktop.