Editing the MSDOS.SYS File

MSDOS.SYS holds some interesting startup settings for Windows that should be explored. All settings they should all be placed in the beginning part of the MSDOS.SYS file under [Options]. Take special care not to change the size of this file!! If you remove anything from it, your system will not start. It has to be exactly 1024 bytes in size.

Logo

This setting simply tells the computer whether or not to display the Windows logo (splash screen) while it loads programs in the background from the command line. Disabling this will ever so slightly slightly increase the startup speed. I disable it because I want to see what's going on behind the curtain. To disable it, include the line logo=0 in MSDOS.SYS.

DrvSpace

This setting tells the computer whether or not to include the DriveSpace compression algorithm for FAT16 hard drives along with the other system files at startup. Disabling this will give an overall boost in system performance, and unless you are using DriveSpace to compress one of your hard drives, it is recommended. To disable this driver, use the line drvspace=0.

Dblspace

This setting tells the computer whether or not to load the DoubleSpace compression algorithm for FAT16 hard drives along with the other system files at startup. Disabling this will speed up the system, and unless you are using DoubleSpace to compress a hard drive on your system, it is recommended. To disable the DoubleSpace driver, us the line dblspace=0.

DisableLog

This setting tells the computer whether or not to create a log file during every system startup. Disabling this will speed up boot times, and since it is unlikely that the log file will ever be used, I recommend it. To disable the log file, include the line disablelog=1.

Additional Information:

• Article 118579: Contents of the Windows Msdos.sys File (Microsoft Knowledge Base)