When I try to install Ubuntu 12.04 on my laptop, it just reboots. I tried with CD, with USB stick, everytime I choose install after 15 seconds it just restarts.
If I install it via Windows with Wubi it works fine. I installed an old Ubuntu version and it worked and then upgraded it to 12.04. I managed to update but it only works (kind of) with kernel 2.6.31-14. If I use kernel 3.2.0-26, it just reboots when you try to load it.
My laptop has 4 GB RAM and an Intel dual core processor and a Nvidia 9200gs 256 MB video card. The board chipset is Via.