The file zcmd.dll is a plugin for RedVex for Diablo II, a proxy that enhances the Diablo experience. This plugin prevents misspelled commands from being sent over the system as messages. RedVex is not an official Blizzard Entertainment product, and users can be banned for using this plugin. If you are having issues with this file, you may need to reinstall Diablo II, or you can try to clean your registry to fix the problems.
When you get an error with a dynamic link library like zcmd, the problem is usually due to your registry. The registry is a database that Windows uses to keep track of all the programs installed on your system. If a file isn’t registered correctly, or has been moved since it was registered, you will get an error when the computer cannot find the file.
Cleaning your registry with ZookaWare PC Cleaner will fix your registry errors, guaranteed. ZookaWare PC Cleaner will scan your computer and make sure the registry is correct. And instead of spending all your time trying to make your computer work, you can get back to gaming.