Ok, after my Windows XP didnt want to work properly I decided to buy Windows 7 Home Premium 64bit.
I formatted my HDD and installed the new Windows system, when it restarted the Windows starting thingy appears, but afterwards when the Desktop etc should appear, theres only a black screen although I can see my mouse and move it around.
I tried it several times, formatting, installing, formatting, deleting partitions, making new partitions, installing, ...
Tried different things, but for some reason all I get is the black screen when the installation is done.
I really dont know what it is, if its the Windows CD (although its brand new) or the HDD or maybe something with the BIOS.
Maybe any ideas?

Do you own an official copy of windows 7?

So it's a official copy
I guess you meet the requirements for Win 7:
If you want to run Windows 7 on your PC, here's what it takes:
-1 gigahertz (GHz) or faster 32-bit (x86) or 64-bit (x64) processor
-1 gigabyte (GB) RAM (32-bit) or 2 GB RAM (64-bit)
-16 GB available hard disk space (32-bit) or 20 GB (64-bit)
-DirectX 9 graphics device with WDDM 1.0 or higher driver
Did you try and google : "black screen mouse cursor windows 7 installation" ? it gave quite a few results but who know what you specific situation is I don't think is anything wrong with the Windows DVD or your HDD.
Good luck.

Oups missed that line.

Abit A8N Fatality Motherboard
AMD Athlon 6000x2
2gb Corsair Ram
XFX GeForce 8800 GT 512MB DDR3
In addition to that I have a HDD with 500GB free space.
So I meet the requiremtns, or am I wrong?

Edit: I googled around a little bit And what I read a lot was something with viruses, the initial reason I bought a new OS was that my old system was kinda infected by various viruses and corrupted stuff. I wasnt really sure if it was something I have to worry about, since it seemed more like an ad to sell some virusprotection, the viruses were located in spaces which didnt exist and they were obviously named like trojan.exe.459, which seemed kinda odd to me. But something was obviously wrong since my internet wasnt working any more and it kinda stopped everyones internet in the whole house, when my pc was turned on.
The question is, can these "viruses" survive although I formatted the whole thing various times and created new partitions?
And by formatted I mean not only c but every partition available.