An old videotape isn't like an old book; its quality only goes downhill with age. And now that digital successors to the VCR are starting to appear in stores, even a mint-condition video may find itself homeless somewhere down the line.

Fortunately, the same digital technology that may eventually doom the VCR also allows you to salvage a collection of decaying VHS tapes. We tested two systems that can transfer old videos to a computer, then archive them in digital form on blank CDs or DVDs.

Both Pinnacle Systems' Pinnacle Studio AV (Win 98 SE or newer, $130, www.pinnaclesys.com) and ADS Technologies' USB Instant DVD (Win 98 SE or newer, $200, www.adstech.com) take an analog video source and funnel it into a computer. Neither offers a FireWire digital port for newer digital camcorders; they include only composite and S-Video inputs.

The Pinnacle hardware comes in the form of a PCI card that requires minor open-case surgery to install in a desktop computer's expansion slot, while the ADS add-on is a compact external module that plugs in to a USB port.

That external hookup alone should make the ADS kit a simpler install, but it requires loading multiple drivers and programs. Pinnacle's installation was more straightforward overall, even though it doesn't include all the cables you might need.

Once set up, the capture process was similar on both systems: Select an input source, type in a name for the video file and click a button. The transfer then proceeds in real time -- but not faster -- with excellent results: Neither kit dropped frames or lost color. Both systems will even copy Macrovision-protected videotapes, so you can archive the movies you bought on VHS.

Once the footage is on your computer's hard drive, the fun begins.

These two systems' video-editing software would have been considered high-end a few years ago, which means these programs are both capable and a potential challenge to newcomers. There's a lot here to learn and manage, but if you can grasp the basic concepts of video editing, both tool kits become reasonably easy to use.

Pinnacle's software effectively streamlines the whole process of capturing, editing and burning video. It's smart enough to detect scene starts and stops automatically, and it also allows fairly sophisticated editing -- you can extract the audio from a clip, then paste it elsewhere in your footage.

It offers more robust DVD-burning features, such as the ability to set up extended menu functions on interactive discs. A well-written, 250-page manual spells out the details, but when it didn't answer our questions, Pinnacle's tech support left us on hold for way too long.

ADS's software bundle is built around a pair of third-party programs: Ulead's VideoStudio 6 for video editing and Sonic Solutions' MyDVD 4 for creating DVDs. This leads to some occasionally awkward mental gear-shifting as you bounce from one application to another.

However, this bundle holds some helpful features. It can create photo slide shows on CD or DVD, and a single-step option will capture video and burn it directly to disc. ADS's knowledgeable tech support also picked up right away.

Overall, USB Instant DVD should be friendlier to beginners. But Pinnacle's setup is a better deal on balance. Also worth noting: Graphics card maker ATI's new All-In-Wonder VE graphics card ($130) includes the same Pinnacle video-capture and editing tools -- plus fast 3-D graphics and a TV tuner -- at the same price.

Whichever system you get, make sure you have plenty of free hard-disk space. You'll need at least two gigabytes for each hour of DVD-grade "MPEG-2" video, and six times that much with Pinnacle's lossless capture option (required if you want to dub footage back onto videotape).

That means you may not always have room to archive entire videotapes. The upside of that limit, though, is that it just might push you to trim those old home movies down to a length that your friends and family will actually enjoy watching.