Anyone got an idea how to compile a gcc from scratch without having any gcc/other C-Compiler installed? I've heard that I have to use some unoptimized-precompiled binary to compile the real compiler, but I have no idea where to get such a thing.

I am looking forward to your replies!

By your profile you have Debian, so you should be able to do:
apt-get install gcc
I believe you'll also need make to compile a standard source tarball:
apt-get install make

Although it's generally easier to just apt-get install rather than compiling...

Yeah, sure, I would do so if I had Debian installed on the machine I wish to have gcc on. But on that machine is a very plain Linux, since it is only a 386 w/ 4mb of RAM.

very simple, you just use a live CD like Knoppix
But I'm not still try about this so it may be wrong

Hm, lauching Knoppix would be difficult since there is no CD-ROM drive.

Also, Knoppix wouldn't run on such an old machine (particularly since it caches a lot in RAM -- I doubt you could even start the kernel with 4 MB).

In fact, I'm not sure if gcc is evcen going to run with anything approaching tolerable speed on a machine that old. But if you want to try there are a number of sites with gcc binaries available. What distro of Linux is on your system (or is it LFS)? If it's from scratch, you will probably just have to find a generic binary (or use a distro's binary), otherwise use the gcc packaged with your distro.