I've done a big error with linux: I've operated without take care or asking to anyone.
I've cancelled College linux first, and Windows xp after, with fdisk (for DOS)...
OK, now this idiot will explain the beautiful result: I reinstalled Windows, but when I reboot, the system doesn't start, and on the screen compared 0101010101010101010101010... and so on.

I tried reinstalling linux, but compared, after the reinstallation during the first reboot, a message of kernel panic, and the computer didn't go on...

May you tell me what can I do to make my hard disk ready for new installation of both the systems?

A friend says to me use Partition Magic, is expensive but good, and will recognise all the shit on your disk.

Good idea for you?

Not quite sure what your talking about so here it is, you probably fdisk'd wrong. not sure what hardrive you have, but if you can get a hold of a program called maxblast use it to zero out your drive. then reinstall windows and linux after windows. windows won't reconize most linux partitions at least windows 2000 did'nt for me. so keep that in mind if this happens again.

also not really sure from your post what you did but the zeros and ones will happen when the boot loader is configured wrong. like its still there but its corrupt or its pointing to a partition but its not pointing to the right place any more.

Yeh but he said he reinstalled windows, so windows should of fixed the MBR, thats why you should start fresh. clean the hardrive then install windows after windows installation then install linux.

did you install windows with a recovery cd or with an actual windows cd? partition magic is nice but not a requirement. it still sounds like a boot loader problem and so if windows did the mbr then maybe a problem with a missing hibernate partition? how many partitions do you have for windows? it maybe poining windows to the second partition cause there should be a hibernate partition as first partition but if its not there...

I've solved the problem:

after I've formatted my disk with partition magic, there were no systems and no partitions, so, when I've reinstalled Windows, the first time I reboot the system didn't start by himself, because wasn't operating yet.

So I used a DOS boot disk to find the boot file in windows and launching it the system started.

The same thing occured after the installation of linux...
Now it's all ok, thank you very much.