longhair

Hi recently I brought a Elgato Game Capture HD knowing it requires 4 GB RAM and my laptop has 4 GB RAM. I Download the software so I can record with it and all was fine, it downloaded fast and easy but when I go to record and use the software it really lags lots and when I go to stop recording after finishing the game play (which I was recording) the capture device is about 5 mins behind. And what made me thought this may be to do with my laptop is one time I tried recording and my laptop just suddenly shut down. I have a 500 GB hard drive so plenty of disk space to save the videos being recorded. Also another thing that makes me think it may be my laptop is that my laptop battery for months has been saying: There is a problem with your battery,so your computer may shut down suddenly. Here is a picture to show what it lookes like: http://i651.photobucket.com/albums/uu238/longhairvids/batery_zpsdba0e4a5.jpg So realy all I want to know is what is causing the lag and how can I fix it? Is it just simple as changing my battery or is it performance of my laptop? Thanks and just to say my mate has a years older laptop then mine which has a 250 GB hard drive and 3 GB RAM and his works perfect to record HD game play with his HD PVR so mine should be ok shouldn't it? Thanks and would love any feed back.