Transferring Video from Camcorder to PC

Don writes, I have recently purchased a Sony DCR-HC21 handycam recorder and am trying download the video and audio tracks from the camera to my computer using my USB Instant Video software. (Unlead VideoStudio 7 SE)
The video as displayed on the camera monitor is good but when I try to copy the video and audio tracks using the camera USB streaming tool, the video signal displayed on my computer screen is very jerky but the audio is great.
The Unlead VideoStudio 7 SE is using the following setup:
Video Bit rate = 4000 kbits
Frame rate 29.97
I have tried all the combinations of settings available on the software package without any success.
Using the AV output connection on the camera and the ADS analog to digital convertor I can get clean (non jerky) but diminished video and audio quality.
Do you have any suggestions to correct this problem?

With any digital video camera, you will get the best quality results when you keep the video in the highest resolution available until you are ready to output your finished movie. You specifically mention your DCR-HC21, but the same rules apply to any DV camera. In this case, you are using USB transfer hardware to import video as MPEG-1. MPEG-1 is a compressed format, generally used for VCD output or digital playback at less than DVD quality. To get great looking video, you need to make a few small changes to the way you import your video from the DV camera to your PC.
The ADS Instant Video hardware you mention here is primarily designed for capturing analog video for import to your PC. It’s also an option for capturing video from digital video cameras, but you are limited by the bus speed of your USB connection, which is variable and depending on the age of your computer, may not be fast enough to prevent dropping frames (the jerky video you describe).
The highest quality format supported by your digital video camera is DV-AVI, the native format of MiniDV tape. The only way to import DV-AVI video to your PC from the camera is using FireWire (also called iLINK or IEEE 1394). The DCR-HC21 and all other digital video cameras include a 4-pin FireWire port somewhere on the camera body. PCs typically have a 6-pin FireWire port. If your PC doesn’t have FireWire, consider buying a PCI FireWire card for under $20. 4-pin to 6-pin FireWire cables are available at most consumer electronics stores. Ulead VideoStudio supports importing video via FireWire, as do most other editing applications.
If upgrading to FireWire is simply not an option, make sure you are giving your computer an optimal environment for capturing video through USB. Eliminate any unnecessary USB devices by unplugging them during video capture, including your printer, scanner, Webcam, or other random devices. In most cases these devices are sitting idle, but occasionally they can take up available USB bandwidth.
One serious gotcha is if you have a USB external hard drive connected while doing the capture. With the video capture and hard drive both vying for time on the USB bus, you can cause a bottleneck resulting in dropped frames. If your capture is routed to a USB drive, seriously consider moving to FireWire for the camera.
Before you embark on any video editing project, be sure to consult my tips on preventing dropped frames during video capture.