Create disk space

Make sure your hard disk isn’t full.

If you’re running just DOS without Windows, make sure your hard disk has at least 2 megabytes of unused space. If you’re running Windows 3 or 3.1 or 3.11, make sure your hard disk has at least 10 megabytes of unused space. If you’re running Windows 95 or later, make sure your hard disk has at least 30 megabytes of unused space.

If your hard disk is too full, some of your programs might act unreliably, because the programmers who wrote those programs were too lazy to check whether the programs would work on a hard disk that’s so full. Some of those programs try to create temporary files on your hard disk; but if your hard disk is nearly full, the temporary files won’t fit, and so the computer will gripe at you, act nuts, and seem broken.

Overly fancy software

Avoid buying and using software that adds many lines to your CONFIG.SYS and AUTOEXEC.BAT files.

The longer and more complicated your CONFIG.SYS and AUTOEXEC.BAT files are, the greater the chance that something will go wrong with them, and your computer will refuse to boot up.

To squeeze more data onto your hard disk, you can use a compression program, which stores your data as a compressed code that consumes less space.

The most famous compression programs are Double Space (which is part of DOS 6 & 6.2), Drive Space (which is part of DOS 6.22 and modern Windows), and Stacker (which inspired the others). Those programs are dangerous: if you accidentally erase them (or erase or modify the CONFIG.SYS file that mentions them), you won’t be able to use any of the data on your hard disk! Avoid using them.

DOS 6, 6.2, 6.21, and 6.22 include two other dangerous routines: Mem Maker and Smart Drive. Avoid using them.

Mem Maker modifies your CONFIG.SYS and AUTOEXEC.BAT files so specific programs get put into specific places in RAM. It’s supposed to make your computer run better but causes this headache: each time you buy another program that modifies CONFIG.SYS or AUTOEXEC.BAT, you must warn Mem Maker; if you forget to warn Mem Maker, the computer has a memory conflict and screws up.

Smart Drive tries to make your hard disk seem faster, by making part of your RAM be a disk cache, which holds a copy of your hard disk’s recently-used sectors. When you tell the computer to deal with your hard disk, Smart Drive makes the computer try to use the disk cache instead of the hard disk, since the disk cache is faster. If you try to write to the hard disk, Smart Drive makes the computer write to the disk cache instead; later, when you seem to be pausing from using the computer (and scratching your head wondering what to do next), Smart Drive copies the disk cache’s contents to the hard disk; but before Smart Drive copies to the hard disk, what if you turn off the computer, or the computer’s hardware or software malfunctions? Then the hard disk’s contents are incomplete and inconsistent. The entire hard disk can become unusable, especially if you’ve been using compression software, which renders your hard drive useless at the first sign of trouble. If you ignore my advice and decide to use Smart Drive anyway, wait 10 seconds before turning off your computer, to give Smart Drive a chance to copy the disk cache’s contents to the hard disk.