I've done something stupid this time.

Three weeks ago I deleted a specific file, and since then he can't boot anymore. The problem is that I don't know the name anymore of that file, but I know that the file contains just 1 number of 4 digits.

Could someone please help me with this problem. I will answer your questions if you ask them.

Any error messages? I think you have deleted one of the init scripts or the files used by them but without further info, it's hard to tell.

If I boot it says:

[drm:i830_wait_ring] *ERROR* space:131040 wanted 131064
[drm:i830_wait_ring] *ERROR* lockup
[drm:i830_wait_ring] *ERROR* space:131040 wanted 131064
[drm:i830_wait_ring] *ERROR* lockup
[drm:i830_wait_ring] *ERROR* space:131040 wanted 131064
[drm:i830_wait_ring] *ERROR* lockup
[drm:i830_wait_ring] *ERROR* space:131040 wanted 131064
[drm:i830_wait_ring] *ERROR* lockup

and this goes on and on and on...

I think its a script file for the monitor, cause the monitor is turning every 5 seconds black...

there has to be a package on your install-CD-s from which the - now missing - file got installed.
since I don't know, where the file you deleted was located, I cannot give you a hint, what
kind(I mean the name) of package you'll have to look for.
With any filemanager (I use "mc") you should be able to look inside those packages and see whats in there - and compare it to what you have (or not) in that place...

But if you cannot get your system up or read on the filesystem another way (like by booting from a rescue-disc or a Live-CD) I cannot help with doing that...

I don't know the location either... damn, I can't believe why I've made such a mess of linux...

I can get my system up, so I can read the filesystem, but I think it's a big task to explore all 3 install disks for any files that are missing on my pc... Doesn't exist a program that automatically can fix this program?

O.K. - I try:

your error message is during boot-up - does it still boot despite this message?

the error message indicates, that there is something wrong (or missing, as you said you deleted something) with drm and your (intel ?) graphics-card.
Now - drm is part of the kernel-drivers for your card.
So I would suggest reinstalling your kernel including the modules.
You did not compile the kernel yourself - did you?
If you did and did not change the source-tree since your last install, then you could just go there and do "make install" and "make install_modules" again - then "depmod -a" to recreate the module-dependencies - and you are all set. Else install from your packages which I hope you still have.

More unlikely, but not impossible, is a missing (deleted) file in your XServer - if the above one does not fix it - try reinstalling X, too.

Next time be careful what to delete while you are root - this would not have happened would you have been working as a normal user...

My kernel is just the regular kernel from the install cdrom. So if I put my install cdrom in the pc, what do I have to do?

...you did not answer the question: does it still boot (are you able to log in) despite this message?

if it does - here we go:

I've never used fedora - I don't know about its package management system and how it is operated correctly.
If it is using .rpm or .deb packages you can install them by hand without the package manager but I do not know the commands for this - probably "rpm -i package_name" or
- for .deb - "dpkg -i package_name"

Even easier is it to use mc (filemanager - if you dont know it, you missed something)
Any filemanager will probably do... Just open the package like you would change to another directory - you then should see a file in it named: install (or similar) open it by pressing enter on it and it should install - _if_ you are root - else you are not allowed to do this.

nope... I can only log on with the rescue disk in my cdrom...

...so, you can get to your system - then go ahead and do what I suggested...

As I told you - I dont have and dont know fedora - thats why you will need to figure out where to find the kernel-package or whatever fedora uses

Maybe I could help, if you could tell me, what is on your rescue disk and if you have others...
How did you install your linux in the first place?

that rescue disk is just an option in a menu of the first install disk. I have just installed linux with those install disks, next to windows. I have multiple OS on my machine...

What you just told me is: your install-disk is at the same time also a rescue disk - which you will need in case something goes wrong and you cannot boot for some reason...so go ahead and use it

1.) can you boot up your system or can you not?

2.) if 1.) = yes --> do it - then look throug your install CD-s for the package (just a file - probably named something like "kernel...version.rpm")

there has to be some package management program in fedora - find out and use it -->

3.) try the fedora-internet-site they surely will have _some_ useful information there as to how to install software and where to find it!