The Windows Installer requires a minimum Service Pack to allow the installation.
As a rule, SimUText follows the Microsoft policies on support for older operating systems. This means that when Microsoft stops supporting systems that have not been updated to include the recommended Service Pack level for a Microsoft operating system, after a number of months, new versions of SimUText will also require the same minimum Service Pack level.
Having the latest Service Pack is always a good idea for keeping your computer up to date. Use one of the following links to download and install a service pack for your system:
Note: The links above are provided for convenience only; no guarantee is made regarding future availability of the linked pages!