when I start the game it begins to download the patch but when I install it says the patch is installed and I start the game again but this begins to re-download the patch and the final states that already had installed the patch and it happens again always
please help with this

Go to game folder \Crysis(R) 2\bin32 and open the game through Crysis2.exe instead of normal Crysis2Launcher.exe.

Maybe this works.

I had the same problem. I had to get back to the 1.8 Exe. Than the (manual) patch worked. If you have win7 you can get the 1.8 by right clicking the crysis2.exe and choosing "restore previous version".