I tried several times to install ubuntu 12.04 on my PC (specs see in my signature). I could determine the layout of the partitions, then format them and start the installations proper. After 53% - 57% of files copied I get a popup like so: "An internal error occurred. Possibly more information can be found in /var/log/messages".

/var/log/messages is not (yet) there, it is a multiboot installation with two openSuSEs and Fedora, thus I can check. This happens with 32 and 64 bit ubuntu from two different (download)-sources. I could install 12.04 on my Acer Aspire One 722 netbook from the same stick.

So up to now I stay behind with no clue at all . I could install 11.10 some time ago on the PC. Any ideas how to proceed from here?

Use the alternate installer cd.

/var/log will be in memory.
open a terminal to see
SMPS issues?
usb stick defective?

Download a whole different CD? Darn, I use a mobile connection with a limited data quota...

How do I access it then?

??? Do you mean "switching-mode power supply"? There are no problems there. The machine runs opsenSuSE 11.4, and 12.1, fedora 16 and ubuntu 11.04 with never any problems there.

No, as I wrote, I installed from it on my netbook (not to mention, that I used three different sticks anyway, just to be able to exclude this as a reason for the problems ).

Did that. Success. I'll mark this thread as solved, since it helped me to reach my primary goal to install 12.04. The error itself (in the other .iso) is not resolved, though, and possibly can't be resolved at all. Ah, well, thanks anyhow amani, btw. any more informations to the questions I asked previously?

In any distro installer,
ctrl-alt-F3 for example will give you a terminal
ls
cd /var/log

etc
ctrl-alt-F1 or F7 to return to GUI

Sure, but I had assumed this works if and only if you have an installed and running system. If I get you right, you are saying that the install process itself is a (running) system too. Now you tell me . Okay, so I know the next time how to access the logs. Thanks, amani.