IRQ Conflicts on Gateway 2000 Computers

• Microsoft Windows NT operating system version 3.1
• Microsoft Windows NT Advanced Server version 3.1
• Microsoft Windows NT Workstation versions 3.5 and 3.51
• Microsoft Windows NT Server versions 3.5 and 3.51

When installing Windows NT on some Gateway 2000 computers, IRQ conflicts may arise because of the default settings for COM ports or modems. If you have a built-in modem, it is usually set up to use COM1 and IRQ 4. There are also two additional COM ports configured as On Board COMA and On Board COMB in your computer CMOS. If a modem is installed, On Board COMA will normally have the following settings by default:

   On board COMA:  COM3
        COMA_IRQ:  IRQ-5

For example, the Gateway may also include a Sony CDU-31A CD-ROM drive which uses IRQ 5 under Windows NT. If you follow the guidelines for installing that device in Windows NT, the CD-ROM still may not work properly. The IRQ conflict can be avoided by changing the COMA_IRQ setting in the CMOS or by setting up the device to use a different IRQ. To adjust IRQ settings, press CTRL+ALT+ESC at a command prompt or during boot to access the CMOS setup (ESC+F1 may also work). COMA_IRQ can be set to 4, 5, 9, or Disabled.

For additional information on using the Sony CDU 31A with Windows NT, query on the following words in the Microsoft Knowledge Base:

   sony cdu

The products included here are manufactured by vendors independent of Microsoft; we make no warranty, implied or otherwise, regarding these products' performance or reliability.