athserver.exe is a application which is probably legit. So, if athserver.exe is on your PC, it is probably ok, and will NOT be a cause for concern. Even if your system is virus-free, we still advise you to use a well-known antivirus with a good track record, in order to defend your PC against threats.
Usually, this application is found in C:\Program Files\TP-LINK\TP-LINK Wireless Configuration Utility\WJATH\AthServer.exe.
The MD5 fingerprint for this file is f33b933902b3a6209db14f35844b534c.
This application is NOT a Windows service. This is good.
This app runs in 32-bit mode. It does not benefit of the entire set of features of current PC chips. This ordinarily happens because the authors did not bother to upgrade it to use the x64 instruction set.
This executable does NOT have visible elements of user interface. This is most likely a bad thing.
A digital signature is missing from this program. The maker did not sign it. This is probably bad.
It has an uninstall string in registry, which is a good sign. si are uninstall.