How to revive an old PC

Last Updated on February 21, 2022 by Dave Farquhar

Somewhere, stashed in a corner of the basement or a closet, pretty much anyone who works on computers or even has just owned computers for a long time has a stash of obsolete hardware, stashed for a just-in-case moment.

Sometimes just-in-case comes quickly. Sometimes not so quickly. It’s when it comes not so quickly that you can run into problems.The first, and easiest problem you’re likely to encounter is a dead CMOS battery. The computer needs to be plugged in and powered on for this battery to charge, and when a computer sits for several years, chances are the battery will go dead. And with it goes the computer configuration, since CMOS memory is volatile, not firmware.

That means all those supertweaked settings you painstakingly entered in after reading Tom’s Hardware Guide in 1996 are gone. But so are the hard drive settings–assuming the hard drive still works.

So the first order of business when reviving a sleeping old PC is just to set it up with a keyboard and monitor, plug it in, turn it all on, watch for a CMOS battery failure message, then turn off the monitor and wait about 24 hours. Come back, turn the PC off and on, and see if you still get a CMOS battery failure.

If not, you’re good. You can go into BIOS setup, autodetect the hard drive if the computer is recent enough to have that feature, and see if the computer boots for you.

If the battery won’t come back, hopefully it’s a replaceable coin type. Remove the battery, take it to Cellular Shack, er, Radio Shack, and they should be able to look it up and find you an equivalent replacement. Buy the battery, tell ’em you’re deaf when they start trying to sell you a cell phone and enjoy the bemused looks you get, then take the new battery home, put it in your PC, power cycle it a few times to see if it needs to be charged, and if not, configure your hard drive.

If the computer doesn’t have an auto-detect feature, the hard drive parameters are hopefully on a sticker on the drive itself. Enter those parameters in CMOS setup, and see if the computer boots.

There’s a very real possibility that the drive won’t work. Some drives react better than others to just sitting. Rather than mess around too much with old drives, I prefer to install an adapter that converts a Compact Flash card (for digital cameras) to an IDE interface. This gives you an inexpensive solid-state drive that won’t develop mechanical problems and will consume less power. You can pick up a Compact Flash adapter very cheaply on eBay. Or you may find an SD card solution more cost effective, these days.

This approach works better on motherboards that can autodetect drive types, of course. I’ve never seen a Compact Flash card that had drive type parameters printed on the label. You can put the card in a system that does have the feature, autodetect it, then write down the parameters so you can enter them in. Or just use the maximum capacity settings your BIOS can handle.

The procedures for loading an operating system vary. MS-DOS and its contemporaries like PC-DOS and DR-DOS, load from floppy. Windows 95 and 98 require boot disks with CD-ROM drivers, which are easy enough to locate online and download. Windows 2000 will boot off a CD-ROM to install, as will FreeDOS and most Linux distributions.

The other major difficulty with older PCs is just that setting them up was more complicated than it is now. With most modern PCs, you can just put in a CPU, connecting a hard drive, and letting the BIOS detect everything. Older boards may require you to set some jumpers for the CPU configuration, and if the PC is really old (especially pre-Pentium PCs), you may have to set some jumpers on plug-in cards as well. You may have to do some detective work, hunting down markings on the board, then do some Google searching (search both the web and newsgroups for best results) to find a manual or a list of settings. Many vendors have gone out of business or no longer have manuals posted on their web sites. When I went looking for a manual for an Asus SP97-V motherboard, for example, Asus no longer had it online. I had to download it elsewhere.

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