My GOG downloader wont maximize it's stuck to the task bar, and i have windows seven... could somebody help me?
a note: i did download one game, but it doesn't work anymore after that!

Try reinstalling it.

I've done that at least 6 times

Oh. :(
Uninstall the downloader. Uninstall Adobe AIR. Restart.
Search the registry for keys made by the GOG downloader (careful not to delete something that you should not!). Delete them, if you find any. Restart.
Install Adobe AIR, install the GOG downloader.
If this does not work, sorry, can't think of anything else, besides, I don't really use the downloader.

I had the same problem. It still downloads while minimized though.

Send a bug report to support.

I had that same problem awhile back.... however support was unable to duplicate the problem... and after a week or so it worked out ok..... strange... thought perhaps my computer had went crazy

Also, as said here you have to uninstall a folder in the Application Data.
Uninstall Adobe AIR folder in C:\Program Files\Common Files\ might be useful too.