Microsoft KB Archive/149564

Poor Performance Reading Video CD in IDE CD-ROM Drive

Q149564

The information in this article applies to:

Microsoft Windows 95

SYMPTOMS

Data transfer can occur very slowly when you are reading a video CD in an IDE CD-ROM drive if the following conditions are true:

The IDE CD-ROM drive is configured as the slave device on an IDE channel, with another device (such as a hard disk) configured as the master device on the chain.
You are using protected-mode drivers to access the IDE devices, including the CD-ROM drive.

For example, playing an MPEG file from a video CD can cause the computer to seem to stop responding (hang) due to the very slow rate at which data is being read from the CD.

CAUSE

There is a problem in the Ios.vxd file that causes excessive seeks on data requests from the CD-ROM drive under these conditions. This results in degradation in the rate of data transfer from the drive.

RESOLUTION

Microsoft has released an updated version of the Ios.vxd file that corrects this problem. The file is:

   IOS.VXD version 4.00.953 (3/19/96, 68,825 bytes) and later

To install the updated Ios.vxd file, follow these steps:

Download the IOSUPD.EXE file from one of the online services listed below to an empty folder.
In My Computer or Windows Explorer, double-click the IOSUPD.EXE file you downloaded in step 1.
Follow the instructions on your screen.

The following file is available for download from the Microsoft Download Center:

Download Iosupd.exe now]

For additional information about how to download Microsoft Support files, click the article number below to view the article in the Microsoft Knowledge Base:

Q119591 How to Obtain Microsoft Support Files from Online Services

Microsoft used the most current virus detection software available on the date of posting to scan this file for viruses. Once posted, the file is housed on secure servers that prevent any unauthorized changes to the file.

MORE INFORMATION

For information about other issues resolved by this update, please see the following article in the Microsoft Knowledge Base:

Q149563 Fatal Exception 0E in IOS.VXD with SCSI Printer

Additional query words:

Keywords : kbfile diskmem win95 kbgraphxlinkcritical
Issue type :
Technology : kbWin95search kbWin95