I have a display problem to trouble shoot just want to
Log in safe mode but F8 control not responding.. need
Help.

More information is required including;
Operating system ?
Machine type ?
Spec ?
Description of the problem ?
What you have tried?

The more information you give the better we can help.

I have a display problem to trouble shoot just want to
log in safe mode but F8 control not responding..need
help.
Try to press the button F2 or F10. While starting of your computer. I hope this should work to configure the settings.