I got a problem, when I power on my PC it boots up normally
then when you arrive to the part where you log in the screen goes black
for about 2 seconds then comes back, after logging in the screen once again goes black for about 2 seconds then comes
back, I do have a DVI adapter because the monitor I have does not support DVI and the graphics card only has DVI ports so I use a DVI adapter, the weird thing is that the green light at bottom right of the monitor never turns to amber it's always green when it goes black.
Restart your computer tapping on the F8 key and select Repair Your Computer.
This will open the System Recovery Options window. Select Startup Repair.
You may also try System Restore to restore your computer to a point prior to this issue.
Also, try this, hope it will work for you:
If you can go to "safe mode" but not the normal mode, there's some type of driver issue, possible the graphics.
First, when you try the safe start, there should be a choice to "start in last known good configuration". Try that
instead of "safe mode". If that still don't restore the normal start, try this next.
While in the "safe mode", go to "my computer", right click and "properties", "hardware" tab, "device manager",
double click "display adapters".
You should see a device, which is your graphic card installed.
Right click and go to the "properties", drivers and click on "roll back driver". This will install the last driver for the
graphic card. Restart if it don't automatically and hope this will fix the problem.