I haven't found any user had this problem which is, when I start LFS.exe it simply does not load. I tried to "reinstall" game but no I had no luck.
I own NV 7900gtx, e6400 cpu, 2gb of ram, ...

Any guess?

Does any other games or programs load slow?

Only thing I could recommend is defragging your PC..

It is recommended that you should defrag ur PC every week or so... it really helps to sort out speed/data issues

I didn't noticed any other program to be slow. I really don't know what to do now. I don't want to reinstall whole OS just because a game is not working ...

If you're adding new skins before you start up LFS it will load a little slower as it has to convert the JPG's to DDS.

That's the only thing I can think of.

Edit: Read OP wrong. Does LFS actually start at all? Run LFS.exe then check in Task Manager to see if it's actually running.

I think I figured out what was the problem. If I woke up computer from sleep mode I could not start LFS but when I restarted computer LFS worked like nothing
I hope that was the problem. If no you will know

Thanks for help anyway.