Cant get to reboot in safe mode

Do you have enough memory to boot the OS?
If so:
1. If this is a desktop, remove one of the extra cards (not video) and reboot. Repeat until you find the problem.

2. If this a laptop, go to bios setup and disable one device at a time, save and reboot. Repeat until you find the problem.
Some laptops have removable cards for Ethernet and wifi.
See 1 above.

BTW what is the system?, memory size?, cards?, devices?

When you hold the button down to get to the power off window, keep holding the button down til the screen goes black and it reboots. If that doesn't work, try taking your battery and sim card out of your phone , put them back in and turn phone on......

Let the machine boot up into safe mode. You'll get a screen that will ask you if you want to go into system restore. Choose YES and it will come up with a calendar of different restore points. Choose a date point where you know the computer was working and then let it restore.
If this doesn't fix the issue then windows is corrupted and you'll need backup your data and reinstall windows completely.

try to boot in safe mode.To do that.
restart your computer continues press F8 key it will show the option select safe mode
and you can work with that and change the reasoluition and restart the computer work with normal mode..

boot to the BIOS and reset the defaults, see if that doesn't get you back into windows

Screen Goes Black After Splash Screen

This sounds like a driver may have been updated, changed or has become corrupt, either after a bad update or virus/malware attack. Reboot the computer in safe mode with networking…when the computer reboots, open the control panel > device manager (in XP the device manager is in the system folder) > scroll to the display adapter. Right click on the adapter and roll-back the driver. Click yes and apply if necessary. Reboot the computer, it should reboot and display with no issue. It may ask (if you are automatically connected to the internet) if it can search windows update for a fresh driver….since you know what to do in case of a failed update, click yes and get a fresh driver. I would then do a complete virus and anti-malware scan to make sure the system is clean.

From your description, you were able to boot the machine properly in Safe Mode. While in Safe Mode, change the video resolution to the lowest possible (color depth does not matter at this point). You should also check that you are configured for single monitor operation if your video card supports multiple monitors. Reboot the machine normally. If all goes well, you can readjust your video settings for a higher resolution again.

RESTART IN SAFE MODE.
OR
REBOOT SYSTEM, BEFORE IT BOOTS PRESS
F6 UNTIL YOU HEAR THE BEEPING NOISE, THAN STOP AND SELECT SAFE MODE
THAN CONTROL PANEL AND SELECT POWER OPTIONS
POWER BUTTON OPTIONS

plz try to boot through safe mode, if you can then log in normally.
if you cant boot from safe mode then you have to reload or repair your os.

During start-up the computer will go to a black screen for awhile and then the pointer arrow will show alone, and then the system will come up.

If you think it's a hibernation problem, pull the ac plug and battery out for about 1 hour and then plug back in.

If this didn't work, then try the F8 Key and choose "Last Know Good Configuration".