If you think that this file contains a virus or another malware, please download a virus scanner.
If rsmui.exe is using too much CPU or too much memory in your system, it is possible that your file has been infected with a virus. Try to install an antivirus to see if it helps.
If you want to remove rsmui.exe from your computer, just go to Start > Control Panel > Add/Remove programs and select Sistema operacional Microsoft® Windows Whistler® from the list.
You may try contacting Microsoft Corporation, the developer of rsmui.exe and ask for more information.