If your older Horizon workstation running Windows XP Pro has been replaced by a new PC running Windows 7, then Horizon 7.4.2 may not launch at all, or may seemingly launch OK but may run oddly or may suddenly quit after launch. Per our website, http://www.lincolntrail.info/HorizonUpgrade/Horizon_Specs.htm, Horizon 7.4.2 is not compatible with Windows 7. Although there have been some posts on the Horizon List Serve, where a few libraries have been successful at getting both to run smoothly, SirsiDynix states that the first support offered for Windows 7 will be in conjunction with the next Horizon release V.7.5.x.
There are two possible solutions that a library may attempt at their own risk, to try and get Horizon 7.4.2 to work on a Windows 7 machine. The easiest is this process:
on the “My Computer” icon on the desktop of the Horizon workstation.
the “Properties” tab
the “Advanced” tab
the “Environment Variables” button
“System Variables”, press the “New” button
“Variable Name” as: HzShrMemBase
“Variable Value” as: 1912602624
<OK> all the way back to the desktop. Reboot the PC.
You should use Horizon for several hours before assuming this solution resolves the incompatibility issue. If it doesn’t, the second possible solution is to download and install the appropriate version, from Microsoft’s website, of the Windows XP Mode product:
This basically runs Windows XP Pro in a “virtual” environment, so it may run slower than on a PC running XP Pro in its native environment. If neither of these possibilities resolves the problem, then the only alternative is to revert back a PC running the Windows XP Pro operating system in its native state.
LTLS is considering a possible late fall upgrade to Horizon V.7.5.x but this has not yet been scheduled because we will lose all custom programming and will need to be 'down' for two days with this upgrade.