In Desperate need of some help with Lightroom on a mac

I've purhcased this week copies of Adobe cs5 production premium, Lightroom and Nik Software. Good old tax return came in finally!
Now i've loaded them all on, but lightroom will open, i then enter my serial number etc and then it goes to continue on ... only to stop with the dreaded error changing modules or something along those lines, now i've googled it, and people say to do something but expect everyone to know their way around a mac ----and i have no idea! I'm pretty good on a PC but not so good on this new imac..... Does anyone know how to help me out? or had this issue themselves and managed to fix it?
I can work in lightroom when i sign in as a guest user but it deletes everything after i exit, so it doesn't really work so well for me! and when i use Nik Software in Lightroom i have to continually keep registering it eveytime i open up any of the software......
I am so over it right now i've got so many pics from my work for the last month i need to complete and i just can't seem to get these new software to work.
So please any help is greatly appreciated.......Ps I need step by step instructions as i barely know my way around a mac! sorry!
kristen
Now i've loaded them all on, but lightroom will open, i then enter my serial number etc and then it goes to continue on ... only to stop with the dreaded error changing modules or something along those lines, now i've googled it, and people say to do something but expect everyone to know their way around a mac ----and i have no idea! I'm pretty good on a PC but not so good on this new imac..... Does anyone know how to help me out? or had this issue themselves and managed to fix it?
I can work in lightroom when i sign in as a guest user but it deletes everything after i exit, so it doesn't really work so well for me! and when i use Nik Software in Lightroom i have to continually keep registering it eveytime i open up any of the software......
I am so over it right now i've got so many pics from my work for the last month i need to complete and i just can't seem to get these new software to work.
So please any help is greatly appreciated.......Ps I need step by step instructions as i barely know my way around a mac! sorry!
kristen