computer will not boot need help

My computer wont boot correctly. I receive a message that states

We apologize for the inconvenience, but windows did not start succssfully. A recent hardware or software change might have caused this.

If you computer stopped responding, restarted unexpectedly, or was automatically shutdown to protect your files and folders, choose Last Known Good Configuration to revert to the most recent settings that worked.

If a previous startup attempt was interrupted due to a power failure or because the Power or Reset button was pressed, or if you aren't sure what caused the problem, choose Start Windows Normally.

Safe Mode
Safe mode with Networking
Safe mode with comand prompt

Last known good configuration

Start windows Normally

Use the up and down arrow keys to move the highlight to your choice.



I was not here when the computer screwed up and dont know how or when it f*cked up. I tried the last known good configuration and it attempted to boot but returned me to the same screen as well as the other options. I havent added any new hardware in about three months and the last software I added was about two days ago and I shutdown a couple of time since then and had no problems booting back up.

I can not boot into safe mode and dont know what I should do next?

appreciate any help