Permanent Swap Files and the Disk Partition Table

The information in this article applies to:

• Microsoft Windows operating system versions 3.1, 3.11

SYMPTOMS

When creating a swap file, you may receive an error message similar to the following:

   The partitioning scheme used on your hard disk prevents the
   creation of a permanent swap file.

CAUSE

This message can result from one of the following:

• A partition manager
• A virus
• Uninitialized fields in the partition table

MORE INFORMATION

Windows is very careful about what hard disks it uses when it creates permanent swap files. Windows would cause serious disk errors and data loss if it incorrectly modified a disk that is formatted with special software. To prevent damaged disks and lost data, Windows makes absolutely sure that it understands the exact format of the disk.

One of the checks performed by Control Panel (and Setup, because Setup uses Control Panel to create a swap file when a custom setup is performed) is to look for disk partitioning software, such as Disk Manager or SuperStor. This is done by examining the partition table on the disk.

If partitioning software is found, Control Panel displays an error message. This message does not imply that the partitioning software is incompatible with Windows; it simply means that a permanent swap file cannot be created on that disk.

The following conditions can cause Control Panel to mistakenly detect partitioning software:

• Another operating system is installed on the computer and happens to use the same partition type number (there are only 255 partition type numbers available); that partition is detected as one using partitioning software. There is no way to work around this problem if this is the cause.
• The machine is infected with a virus. Some viruses create their own "foreign" disk partitions and set themselves up as the boot operating system (for example, the Michelangelo virus). If no other explanation for the disk partition error can be found, the disk should be scanned for viruses. When the virus is removed, Windows should be able to create the permanent swap file.
• The disk drive may have been partitioned in the past with partitioning software, and was later repartitioned using MS-DOS version 4.01 or 5.0 FDISK. MS-DOS and FDISK support only four partitions on a disk, while some partition software supports more than four. Therefore, FDISK does not reset partitions in the extra entries. As a result, Windows interprets these invalid entries as an incompatible disk partition.
• Ontrack Software Disk Manager-N utility partitions and formats part of a hard drive as a Novell file server. When a machine configured with Disk Manager-N is started, the Novell utility attached to the master boot record (MBR) loads and gives you the option of starting the system on the MS-DOS partition or to the Novell file server partition. If your hard disk has been partitioned with Disk Manager-N, you cannot create a permanent swap file under Microsoft Windows 3.1.

  The following text was taken from the Disk Manager README file:

        DISK MANAGER - N
  

        DISK MANAGER - N is a disk installation utility tailored
        specifically for the NOVELL local area network. This utility
        replaces the COMPSURF utility from NOVELL. DISK MANAGER - N
        installs disks running under NETWARE 86, ADVANCED NETWARE 86,
        and ADVANCED NETWARE 286.