Just trying to help.
Sounds like you have a Digital 8 tape based camcorder. (The same information can be used with a miniDV tape based camcorder.)
We don't know what you are trying to us for playback that is resulting in the symptom you report (sound only - no video). Installing and using VLC player from www.videoLAN.org is a great idea. It is a lot more robust than many other media players. If this resolves your issue, great. If not, the method you are using for importing may need modification.
To get the video from the tape in the camcorder into a computer there are two ways:
Camcorder off. Connect the camcorder's 4-pin DV/i.Link/IEEE1394/firewire port to the computer's firewire port with a firewire cable. Connect the camcorder's AC adapter to the camcorder and a known working power outlet. Power up the camcorder and put it into Play/Edit/VCR mode. Rewind the tape. LOCK the tape if it is not already locked. In the computer, launch the video editor and import/capture the video. If the bundled editor does not recognize there is a camera, download/install WinDV. I've seen it work where others could not.
USB won't work. USB-to-firewire cable/adapter/converter things will not work. Thunderbolt firewire adapters work great (don't think we have an opportunity here, just being complete).
We know nothing about the laptop you are using - other than it is running Windows XP. If it has an available PCMCIA or ExpressCard expansion slot, a firewire port can be added. If there is no available expansion slot, then we go to plan B:
Using the camcorder AV cable(s), connect the camcorder's AV-out to the AV-in of the analog/digital converter. Connect the A/D converter's USB port to the computer's USB port with a USB cable. Power up the camcorder and put it into Play/Edit/VCR mode. Rewind the tape. LOCK the tape if it is not already locked. Usually, the A/D converter comes with some sort of importing software, Launch that. Import. When done, quit, then launch the computer's video editor.
With the step through analog (from the camcorder to the A/D converter), there will likely be a reduction in video quality. Since this is all standard definition video, it will not be that noticeable. Legato, Black Magic Designs make good A/D converters. Lots of others, too - some as good, many not as good.