Failed to install runtime with error code 1601

Failed to install runtime with error code 1601 is an error message reported by ClamAV (and possibly other applications) if you attempt to install it from "safe mode" in Windows XP.

Apparently XP runs an "installer service" which is unavailable in safe mode. It's not clear whether applications must use this service in order to install properly, but it seems likely.

Links

 * win installer error code 1601