WriteLog, as of this writing at version 12.97, depends on the Microsoft VC++ redistributable runtime. Microsoft publishes the downloads for those kits at https://learn.microsoft.com/en-us/cpp/windows/latest-supported-vc-redist?view=msvc-170#latest-supported-redistributable-version. The WriteLog installation kit includes an installer taken from there, and automatically invokes it after installing WriteLog.
However, as of about May, 2026, Microsoft has chosen to make those redistributable installers refuse to install on Windows versions older than Win10. The result on Win7, for example, is that the WriteLog install appears to succeed, but is followed by a nasty-gram from Microsoft. And the nasty-gram is accurate in the sense that WriteLog won’t work yet because the needed VC++ libraries are not installed.
However, there is a workaround. Those same libraries are also available in downloadable from from https://github.com/abbodi1406/vcredist/tags. As of this writing, the kit at the v0.104.0 tag works. WriteLog needs only the one named VisualCppRedist_AIO_x86only.exe. On Windows 7, after installing WriteLog and gotten the failure message above, and after having clicked OK on all the error boxes, download the x86only kit and run it. After that, WriteLog should be good to go. If there is still a problem bringing up WriteLog after this x86only kit install, try again running the WriteLog installer, click OK on all the error boxes that come up and try to run WriteLog again.