hey guys,
so today i was recording gameplay on the map zombie seelow and i was using camtasia studio 8
i went back to the gameplay and all it showed was my desktop

does anyone know a recorder that is reliable and free?

http://www.youtube.com/user/Heatzio

Bandicam demo offers 10minutes per-recording and is great when it comes to saving up on disk space. It automatically convert the video in realtime, but uses CPU quite too much for me.
Fraps is best when you want best performance although 2-hour gameplay takes 120GB of disk space

Fraps is good, I've been using it for a while without issue. Some also enjoy DXtory, its more complicated but can give you better results in the right conditions. Both cost though, your not gonna get anything good for free.

You can use Camtasia, just record the game windowed. Fraps and Dxtory are also good.

i use bandicam, you can record 10 minutes with the trial but if you want to buy it, it costs $40. but its worth it, file size is small and it can record in hd.

The Razer Game Booster has a free video recorder and screenshot capture, I used a version of this for a while. It's ok and it's FREE.
http://www.razerzone.com/gamebooster

thats what im using the razer and believe it or not its great