Which software do you need?
Apart from the Game Flow Analysis Tool you will need a video capture software solution. Two excellent tools are available, but both of them don't work with every game. Therefore, using one of those tools along with an incompatible game may result in poor performance. So far, one of those tools always did the job when the other one didn't.
Camtasia is a commercial software package by Techsmith.Its main advantage lies in the free choice of codec. That way you can compress a video using DivX, which shrinks the file considerably while keeping the quality high.
FRAPS is also a commercial software program, which you can download here. Unfortunately, FRAPS uses its own codec only, so if you don't want the video to be split up into several files, you have to select a smaller resolution.
DirectX is used for video playback. In addition, the Game Flow Analysis Tool requires .NET 2.0. Both Microsoft software packages are free and available online or a part of Windows.
You need to keep an eye on two hardware components, if you don't want the video recording to interfere with the performance of the game: the hard disk drive and the CPU.
Hard disc drive
Since the video capture software streams the data onto the HDD and the game itself needs to access the HDD as quickly as possible, you should consider installing a second HDD for video recordings in your test system. The additional HDD is then to be used for storing video files only. For the best possible data transfer rate, make sure any external HDD supports eSATA rather than USB. USB suffers from a comparatively low bandwidth, which can become problematic when dealing with uncompressed video files. In addition, data transfer via USB may increase the CPU load.
If you want to make use of high-level video compression, you need to have a multi-core system. So far, only few games make full use of two cores, which is why a dual-core CPU will suffice at the moment. Still, surely there will be a time in which CPU's with more than two cores will be used to avoid losing CPU resources for compression.