Safe Mode??

Have a nearly 7 year old Dell XPS9100 desktop I am trying to save. I cannot get it to go into safe mode. Any ideas?

Issue is ... Was on one evening with mail, ebay and Facebook open. All the sudden it froze on me. I couldn't do anything. Nothing would respond. I waited and waited and waited and finally, I did a forced shut down. Since then, when I start it back up, it goes all the way to the log in page where I input my password and then it goes to just a black screen. Have attempted to get into safe mode (F8 key) numerous times but for whatever reason, it won't get there. I'm at a loss now as to what to try next.

P.S. I should mention that I also installed a brand new graphics card thinking that the graphics card in there, could possibly have gone south on me. After I installed the new graphics card and I restarted, a DIFFERENT page came up with 2 options ... one was a "recovery" option and the other was a "Try A Restart" option. Thinking it MIGHT be the graphics card, I chose the "Try A Restart" option and ... nothing. Same black screen. I tested the monitor and it works fine. I pulled the memory cards out and reseated them while changing the graphics card. Still, just the black screen after I input my log in password. Now, at a lose as to what to think OR try next.

Many thanks in advance ... CWFan2