Hydro Plus/Prolock Program Hangs with DOS=HIGH (79236)

The information in this article applies to:
    Microsoft MS-DOS operating system 5.0
    Microsoft MS-DOS operating system 5.0a
    Microsoft MS-DOS operating system 6.0
    Microsoft MS-DOS operating system 6.2
    Microsoft MS-DOS operating system 6.21
    Microsoft MS-DOS operating system 6.22

This article was previously published under Q79236


Plus 3 Software has confirmed Hydro Plus engineering package will cause system hangs if MS-DOS is loaded into the high memory area (HMA).

Vault Company produces a security program called Prolock Security System that must load before Hydro Plus may be accessed.

To resolve the problem, disable the following line in the CONFIG.SYS file:



Hydro Plus uses a security program by Vault Company called Prolock Security System to run with Hydro Plus. This security program must load before Hydro Plus may be accessed. It is the Prolock Security System that causes the system hangs, not Hydro Plus. Plus 3 Software recommends loading MS-DOS low, or in conventional memory (that is, not in the HMA.)

The Prolock Security System program code is incorporated within the Hydro Plus program code. The security program expects a "wrap-around" when calling a memory address beyond 1024K. When MS-DOS is loaded into the HMA (which is between 1024K and 1088K), a memory "wrap-around" is not performed and Prolock Security System will cause the system to lock up. Extended memory may be accessed along with the upper memory area. It is only the DOS=HIGH line in the CONFIG.SYS file that causes the system to hang.

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

Modification Type: Major Last Reviewed: 5/12/2003
Keywords: KB79236