Windows

It's a real problem. You don't mention your OS or processor, but

It could be your mouse:
http://support.microsoft.com/support/kb/articles/Q143/0/53.asp

It could be very complicated:
http://www.dolphinuk.co.uk/support/TechBulletins/tech82.htm

There could be a quick fix:
http://www.annamaria.net/tools/Ios.htm

If you have an AMD processor:
http://discussions.virtualdr.com/Forum1/HTML/002556.html

Well it could be as simple as this..

Free up some conventional memory!!
I did have this kind of problem once, and started to optimize the startup sequence by freeing up convnetional memory.

Markus

Here is a list of items known to cause the error and their fix:

PROBLEM- If 'low memory' is part of the device ios error,

FIX- Go into safe mode, at the run line type 'system.ini', click ok, add this line under [vcache]'maxfilecache=6144',save, and reboot the system.

PROBLEM- Resource conflicts (IRQ, I/O address, etc...).

FIX- Disable any onboard items such as video, sound, and network if a card performing the same function is installed in a slot. Check for duplicate drivers installed under a device in device manager while in safe mode.

PROBLEM- Driver is corrupt.

FIX- Reinstall or update the drivers for devices that do not start in safe mode.

PROBLEM- If client software is installed (Client32) for the network.

FIX- May need to be reinstalled.

PROBLEM- If the error came up after installing software and rebooting.

FIX- Rename smartdrv.exe and restart the system.

PROBLEM- Random device ios errors.

FIX- The problem can be caused by bad RAM that would need to be r

I think the conventional memory idea is a good one, Do you have in your config.sys file...
device=c:\windows\himem.sys
device=c:\windows\emm386.exe noems
dos=high,umb
and any cdrom or other device's being loaded high (devicehigh=c:\cdrom\driver.sys..)
and in autoexec.bat, load high commands
(lh c:\windows\command\mscdex.exe ...)
These are all ways to optimize your conventional memory useage, I have verified that and changed setting acordingly on a number of windows protection errors, and it works about 50% of the time!
Good Luck...

Check out Microsoft Knowledge Base article Q157924-Err Msg:"IOS Failed to Initialize" on Boot