Fraps is notorious for its ridiculously huge video file sizes. Even at 720p a 5 minute video is around 6-10GB (depends on the settings) I presume at that resolution and fps (providing you won't be using losless RGB) just a few. I suggest
- converting your video via Format Factory, Handbrake, Freemake Video Converter etc.
- try a different screen recorder like Action, D3DGear, Dxtory etc. (do you have a gtx 650-up? If so, use Shadowplay from the new nvidia drivers)
- if possible, get another hdd with 2-3tb capacity to be safe
But I'm not entirely sure. You could try recording a test video with Fraps with your preferred settings and do something like 5-10 minutes and see how it works out.