I decided to install Ubuntu 12.04 alongside Win 7, which is a primary system. I downloaded, checksumed, and burned iso to DVD. Then I installed Ubuntu using general instruction, the only thing I changed was allowing manager to partition disk space automatically (though I shifted to 200 Gb out of 300 Gb, not sure how much I need).
After completion I rebooted system, and with DVD off machine it launched Win 7 without prompting me. Turning on DVD, it again asked me to install Ubuntu. The problem is that it took off those 200 Gbs out of hard drive on Win 7.
So first, what the problem might be? Did it happen because I partitioned wrongly? I'm actually not sure, when I asked to allocate space, is it size of hard drive that can be used to install programs, or it's just to install Ubuntu onto that?
Now when I decided to reinstall Ubuntu using other instructions, how can I find out what partition was allocated on Ubuntu on Win 7, in order to manually allocate space next time?
My final goal is to allocate enough space for all programs on Ubuntu (as I understood I'm not able to use programs from Win 7). If for instance I want to have 300 Gbs, should I pass that much space during installation?