Not enough conventional memory.
If the game is running in Windows, a boot disk is recommended. If the game is being run in DOS, use the MEM command to check what the largest executable program size is. Check the reference card or install guide for the minimum conventional memory required to run the game. You may want to reduce the amount of drivers being loaded if possible. You may also want to consider using EMM386 if the game is compatible with it, and try to load drivers into upper memory by using DEVICEHIGH when loading a file in the config.sys or using LH when loading a file in the autoexec.bat. See the Memory Management Guide for more information.
Invalid system disk.The disk being used is not bootable. If you are using a floppy disk, you can type FORMAT A:/S to erase the disk and make it bootable or SYS A: to just make it bootable. Make sure when you are formatting a floppy disk that the write-protection slider in the upper corner of the disk is down. The hole should be filled in. See the Boot Disks Guide for more information.
Bad Command or File Name.The command you are trying to run does not exist. Check your spelling carefully. Also make sure that the command you are trying to run is in the directory you are currently in or specified in the PATH line.
Invalid Drive Specification.The drive you are trying to change to or interact with does not exist or is not detected by DOS. This is often caused by the CD-ROM Drivers not being loaded correctly.
CDR101 Error.Make sure the game disc is in the CD-ROM drive and that the CD-ROM drivers are loaded correctly. See the DOS Drivers Guide for more information.
VESA Driver not loaded.Some older video cards do not meet the VESA (Video and Electronics Standards Association) standard. The VESA standard is 640x480 resolution and 256 colors. The instructions on how to display these settings are usually on the video card itself. Some video cards do not have these instructions built in, and a VESA Driver is required to provide these instructions, If a VESA Driver is required to play the game, it is recommended that you contact your computer or video card manufacturer to obtain one. If you are unable to get a specific VESA Driver, you can get a universal VESA Driver that may be compatible with a wide array of video cards.
Too many parameters.Chances are a command was inserted where it doesn’t belong. Also, check which slashes you are using. DOS considers the backslash (\) and the forward slash (/) to be two very different commands.
Mouse required.A 16-bit mouse driver was not detected. Make sure you are not trying to run the game in Windows. If the game is trying to be run in DOS, make sure you are using a compatible mouse driver. A good way to check to see if the mouse is working is to type EDIT. If you can see the mouse cursor, the mouse should work with the game. See the DOS Drivers Guide for more information.