This is the most reliable "official" source. You can find version 7.14.10.5290 (released in 2010) specifically for Windows 7.
Since these drivers are older, the standard "setup.exe" doesn't always work. You may need to "force" the installation through the Device Manager . Windows 10 Forums SiS Mirage 3 Drivers for Win 10 Pro x64 - Windows 10 Forums download sis mirage 3 graphics for win7
If you have a laptop from a brand like Dell or ASUS, they may still host these drivers. For example, Dell Support hosts a version compatible with Windows 7 32-bit. This is the most reliable "official" source
Because SiS no longer maintains an active download portal, you must rely on archives and manufacturer support pages. You may need to "force" the installation through
Platforms like DriverScape and DriverIdentifier maintain repositories for older 32-bit and 64-bit versions. Step-by-Step Installation Guide
If you're still running Windows 7 on an older machine, finding the right can be the difference between a functional computer and one stuck with a blurry, low-resolution screen. While Silicon Integrated Systems (SiS) has long since stopped official support, it is still possible to get your hardware running smoothly with the right steps. Where to Download SiS Mirage 3 Graphics for Windows 7