Hey, i found this site a few hours back and buyed my first game, but when i try to install it . Part 1 out of 3, it's corrupted? Any help? Thanks.

Disable your antivirus and firewall. Also, are you using the downloader or your browser?

Download again. Sometimes the DLs will get corrupted. Make sure you have all the parts though, and in the same folder, and don't try to unpack them. Just run the .exe installer and the game should install fine.

1) If the game is large (>2GB) make sure you download all the parts.
2) If you have all the installer parts, and one of them fails the integrity check, it became corrupted during the download, thus you'll have to download it again.
I'll also suggest you grab the downloader, since it does an integrity check while downloading, thus should help prevent corrupted files. Check the stickies on the top of the forum for more info.

Just using the normal download, yes. Just clicked Step 1 out of 3, And i don't feel that safe about turing me antivirus and firewal off.

Don't worry, nothing will happen :) Just stay on safe sites while you're doing it and you'll be fine.

You only have part of the installer then. You need all 3 files.

Wont let me use the GOG Downloader..?

A bit more info? You downloaded and installed the downloader, then switched the "Off" button in your account to "On", and then clicked on "Windows Installer"? What happens then?
Also, what browser are you using?

No problem, enjoy your games. Should you have any more questions, don't hesitate to ask, there should be a few people willing to help.

You don't need to browse at all to be infected - just be connected to the internet and worms will find you if you don't have a firewall.