Hello! Nice to meet everyone.
Firstly, thanks for reading. I've been a ubuntu user for a while, and now I decided to work using Mint, but I did a fresh install of Mint 12 KDE and it's not going very well. The live DVD booted to a black screen, which was easily solved adding the nomodeset option; then, after installation was finished the system booted to a black screen, with no login screen at all, and adding the nomodeset option in the grub options didn't help, it still booted to a black screen. A couple of months ago I had a similar problem with kubuntu 11.10, but that time at least I was able to get to the login screen and from there start a tty session to install drivers and missing packages. Based on that experience I tried starting in the rescue mode from the grub boot menu list, so I choosed that said option and was able to login with my user name and password, the problem is that the system won't let me install anything at all, b.e., simply typing sudo apt-get update returns a message telling that url's could not be retrieved and that /var/lb/dpkg/lock is a read-only file, the same if I try to install a package. I found people with similar problems in other posts, but everyone solved it reinstalling, I could try to, but this is the 3rd time this week I try to install an ubuntu based system in my computer.
Aditional data? My video card is an nvidia geforce go6150 (rather antique). I'm trying to install linux alongside with Win7, from which I'm writing right now, with no graphic card problems or similar issues. The systems I tried to reinstall this week were: Kubuntu 11.10, kubuntu 12.04 and this time Mint 12 KDE, all from the same line and in 64bit version. I haven't tried yet to install an older verision like 10.04 and updating from it, mainly because I read in other posts that the black screen problem was triggered after an update.
Well however I hope someone here has a clue, I really want to work with mint, I just don't feel comfortable in windows; I'm really skilled yet in linux and command line usage but I'm willing to do some research if necessary. Thanks in advance.

