Looks like a dump file after each blue screen offers a program to be killed - the one that causes all the troubles. I found BlueScreenView wich is supposed to search and show those dump files. I have windows 7 and I read that Daemon Tools can cause it here, but I don't have Daemon Tools so I'll see what it is. By the way, the blue screen is always pixelated so I can't see the problem when it happens.
I clicked on Google Search in BlueScreenView and it searched for "IRQL_NOT_LESS_OR_EQUAL ntkrnlpa.exe". Looked like I'd have to buy a new RAM or to update some drivers. I chose the later. I ran "sfc /scannow" in DOS... it didn't help much, I got too many unfixable files at C:\Windows\Logs\CBS\CBS.log.
More and more I'm starting to think about formatting the whole partition (I have Linux with GRUB). The problem with netbook is that there is no a software I can install. Lenovo has the flash drive with the windows on it. I don't. So far I'm getting a blue screen aproximately once a day.