Microsoft KB Archive/104544

From BetaArchive Wiki
Knowledge Base

Cannot Uncompress Some Floppy Disks Without Removing Data

Article ID: 104544

Article Last Modified on 11/21/1999


  • Microsoft MS-DOS 6.2 Standard Edition
  • Microsoft MS-DOS 6.22 Standard Edition

This article was previously published under Q104544


This information applies to both Microsoft DoubleSpace and Microsoft DriveSpace. For MS-DOS 6.22, use DRVSPACE in place of DBLSPACE for commands and filenames.

If you compress a floppy disk and immediately try to uncompress the disk, you may receive the following error message:

DoubleSpace cannot uncompress drive <letter> because there is not enough space on drive <host letter> to hold all of the uncompressed files.

To uncompress drive <letter>, you must remove at least <xxx,xxx> bytes of files from either drive.


This occurs because DoubleSpace is very conservative in estimating the space required to hold the uncompressed files. The estimate is based in part on a worst-case scenario in which the data on the floppy disk is stored at a 16:1 compression ratio and DoubleSpace must convert the drive from a 16-bit file allocation table (FAT) to a 12-bit FAT.


To work around this problem, remove <xxx,xxx> bytes of data from either the compressed drive or the host drive.

Additional query words: 6.20 diskette

Keywords: KB104544