need help asap( noob mistake)

so, ive had my laptop since march. firsst computer that was mine to do with what i will. and im somewhat tech savy so i usually investigate things and figure them out. today i was looking at my computer info and noticed it was showing a lower ram value then what i had. so i looked it up and seen a post about msconfig. i went to it, clicked advanced options, and the max memory was at 4XXX when i have 6gb ram. so i tried to change it and noticed when i clicked ok it would change to 0. tried it a couple more times and same thing. so i clicked accept(stupid me) and restarted it. then bsod came up and just kept looping over and over. tried to get into safe mode which if im right is shift and f8 for windows 8? but it didnt work. all i could do was hold f2 and it would bring me into a thing, tried to set defaults and that didnt work either. id really like to figure this out. any help would be appreciated.

toshiba satellite c855-s5134
2020m dual core processor 2.4ghz
6gb dimm ram
500gb hdd 5400 rpm