Knowledge Base |

# Maximum Number of LPT and COM Ports

Article ID: 100111

Article Last Modified on 5/4/2005

APPLIES TO

- Microsoft Windows NT Advanced Server 3.1
- Microsoft Windows NT Workstation 3.1

This article was previously published under Q100111
The maximum number of COM and LPT ports that Windows NT supports is 256. This is a limitation in Control Panel and does not represent a limitation of the hardware platform. In both Intel x86 and MIPS machines, the number of COM and LPT ports is only limited by available interrupts, I/O addresses and, ultimately, 4,294,967,295 (32 bits).

Additional query words: prodnt

Keywords: kbother KB100111