I have а problem with my laptop's memory

chainsmokerbg

Honorable
Sep 23, 2016
14
0
10,510
Hello guys so I have this problem, I had 4 GB RAM on my laptop but only 2.92 GB was usable so I wanted it to work on 4GB because I was running a x64 version of windows. I opened msconfig and I clicked on Maximum Memory but I didnt realise that it was 256 on there not 4096 and I clicked apply then I restarted my laptop and now I can't turn it on to my Desktop. It only goes to the Windows icon and then goes blue screen saying to make a memory diagnostic but my F8 doesn't work... I've tried to run a Memory Diagnostic, System Repair, System Restore and also reinstalling the laptop but I couldn't becuase I wasn't able to open the boot menu because my F keys didnt open it I don't know why. Please help