If you specifically need WinMount, you can find the 64-bit installer on these community-trusted software mirrors:

(free for personal use)

Because WinMount is abandoned and lacks 64-bit support, you are better off using modern tools that offer the same functionality.

(64-bit, free, open-source)

WinMount’s primary function is creating a virtual drive that treats a compressed file like a physical hard drive. This saves time because you don't have to unzip large files.

Before proceeding, you must understand the current state of this software:

Allows you to create a temporary blank RAM-disk (ranging from 64MB to 4GB). Modern Alternatives

Mount archives (MOU, RAR, ZIP) and disk images (ISO, BIN, MDF) as virtual drives.