An I/O subsystem driver failed to load - Reboot only in Safe Mode

Last Published: April 25, 2020

Solution or Workaround


ArcView 3.1 and Crystal Reports installed successfully. After rebooting the system this error occurs:

Error: An I/O subsystem driver failed to load
Either a file in the .\iosubsys subdirectory is corrupt
or the system is low on memory.

Upon rebooting, a 'General Protection Error' message may also occur.

After this, the computer will only reboot in Safe Mode.


According to Microsoft, this problem may occur when all memory below 1MB is allocated prior to initialization of Ios.vxd. Ios.vxd needs memory below 1MB for use as real-mode buffers, if it can't do so, it fails to load, and Windows 95 fails to boot.

Edit the system.ini file as follows:

1. Find the area marked


2. Beneath it, type this line:


You should now be able to reboot normally.

Article ID:000001509

  • Legacy Products

Get help from ArcGIS experts

Contact technical support

Download the Esri Support App

Go to download options

Discover more on this topic