I am having a serious issue with all my apps disappearing/not working- user profiles

also, my usernames are being treated as equal atm, i can log in using either tbd or my name same password and everything, but the master password is different under users and groups- i asked the guy i bought it from for it, waiting for a response

also i forgot -i changed under sharing the name from his to my name in the past 24

i had one mac and spilt water on it, the motherboard fried so i had to buy a used one...being in school and all. it is a MC375lla

Sudden Motion Sensor:

i do not have a backup of it, so i am thinking about replacing my old hard drive from the water damaged into this one, not even sure if that would work, but it did not seem to be damaged, as i recovered all the files i wanted off of it to put onto this mbp

the previous owner didnt have it set to boot, they had all their settings left on it and tried to edit all the names on it, had a bunch of server info and printers etc crap on it. i do not believe he edited the terminal system though--he doesnt seem to terribly bright(if thats possible)

tbh i hate lion compared to the old one i had, this one has so many more issues-overheating,fan noise, cd dvd noise

if you need screenshots or data of anything else as away

[problem is i do not want to start from scratch if there is a chance of fixing it, this one did not come with disks or anything like my first. so i dont even know if i could, and how it sets now i am basically starting from scratch, because now all my apps are reset but working, i am hoping to get my data back somehow though, i lost all of my bookmarks and editing all my apps and setting again would be a pain

tbh it seems like the files just got moved to the wrong place because in my system report all of my apps are still there but they maybe couldnt find their settings from a username change? i dont get why now my username says my name(tbd) like it tried to combine them or something

edit: adding to this i have 3 folders under users my name with everything i had before/ shared/ and tbd which has no documents music etc

oh ha yeah, my last one was considered "early" 2010 but he still did not provide me the disks....that will take hours to copy all the files, but i will give it a shot... thats basically how i screwed it up, was by making a second profile and not copying everything over. I guess no matter what i have to start over, i cant even think of all the stuff i will be missing that needed researched or work done from my bookmarks and backups but oh well.

unless you think these bookmarks could be saved somewhere? i used mozilla and i was just googling it and havent found anything yet when i saw your response

actually it says 20 mins for 50 gb so thats not bad...quick transfer, from the other forum do you think he meant things get messed up if i were to delete the tbd? or just in the transfer process?

actually my biggest concern about this transfer, after screwing up my computer, will i have to resync my iphone with my computer? because i have done that for other reasons and i have to manually do it making it a pain in the A took me 5 hours last time smh...

i have no idea what the mbp is thinking though, idk what process caused this to happen, or else i would figure a way to undo it. i cannot restore it and i dont need tbd's space so i guess i will leave it on until it comes to that. from now on i will keep backups again. my mac pro is always backed up and so was my last mbp but i hate this machine it doesnt make any sense and runs like crap(hot, low sound, not bright-had to get aps for the first two), maybe ill just sell it on fleabay where i got it thanks for the help =]