I tried using microsoft movie maker, but the speed is inconsistent.
If you're just capturing, it should be real time transfer. I've used MovieMaker a few years back and I can't remember exactly, but it might be capturing to some kind of compressed file format (WMV, etc.) so see if you can change the settings so it captures the video into a regular NTSC DV (or DVCPRO) encoded AVI file. The files will be large, around 13 gigs per hour tape, but you'll get original quality video.
As a note of caution, if you capture on a Mac, it'll give you files that might not work on a PC without an extra conversion step. For example, iMovie returns DV stream files in a Quicktime container, which you'll need to conver to AVI to work on a PC in MovieMaker or Premiere Pro, etc.