I have no idea of which installer you used but this should fix it, as long as you don't have other servers installed in the same folder as heRO's.
Go to
Ratemyserver.net and then to
Downloads > kRO Clients. Once there click in one of the "
<Host Name> file folder for all 9 files" and look for the file with DLL in the name (if you pick
Depositfiles, you will see "
ro10182013_dll.rar" for example) and extract its content directly into the root of the folder where you've installed heRO (the root is where you see all the EXE's and whatnot).
If you're confused click
here (credits to Ratemyserver.net) to download "
ro10182013_dll.rar" and extract the content wherever your folder with heRO is.