rstray.exe is part of Rising Antivirus developed by Beijing Rising Information Technology...see here
Rising Information Technology is legit and there is a Rising Support website
but it is only in Chineese.
According to their former English website
We will terminate the Rising official English website, including website information, purchase and renew services and online technical support as from September 09, 2013.....you may call customer service (8610) 82678800 or 4006608866 (toll-free) for further help.
The correct way to remove most Anti-virus programs is from within its program group Uninstall shortcut in Start Menu > All Programs or by using Programs and Features
) in Control Panel.
If it's not listed there, the next step would be to open Window's Explorer, manually navigate to the program's folder itself, look for an uninstaller file (i.e. uninstall.exe) and double-click on it to run. In other cases you may have to launch the antivirus setup
and in the menu there may be options listed
to Reinstall, Repair, or Remove
Alternatively, you can use a third-party utility like Revo Uninstaller Free or Portable
and follow these instructions
for using it. Revo provides a listing of all installed software by installation date and when removing a program, Revo does a more comprehensive job of searching for and removing related registry entries, files and folders.
Sometimes the uninstall works more effectively if you first stop and disable the program's service
(and associated processes in Task Manager) or perform the removal in safe mode
so there are less processes which can interfere with the uninstallation.