linux newbie need help with graphics drivers

ok so the other day i installed linux mint 13 on my old dell optiplex gx270 2.8ghz pentium 4 with nvidia geforce 5500. so the install went alright but i had to do it in compatibility mode. when i went to strart it after installed it went into a nlack screen that was asking me for user and password. so i googled a bunch tried a few different things untill finally i got to the desktop. i think at this point it was in a graphics safe mode. i restarted the computer and it didnt load me into the safe mode andd now if i try to open anything it doesnt show anything on the window its just blank so i cant get anyware to download drivers or do anything else. so i was wondering if there is a way to fix this or get me into graphic safe mode or anything. it installed alright on my laptop and i really like it so i want to use it on my desktop.

the thing to try is booting into console mode and editing xorg.conf - you want to change it to use the vesa driver. check google/Mint documentation for exactly how to do that (unless a Mint user here can give you the exact commands).

you can also try setting the kernel command line argument to prevent kernel mode setting - see Mint thread here.