Do you have a program called AOMEI Backupper? This program conflicts with RealPlayer.
As a workaround, you can follow these instructions to resolve the issue.
1. Right click on My PC
2. Click on Properties (This should open System Properties)
3. Click on the Advanced tab and click Environment Variables button
4. Select the "Path" where you see "AOMEI Backupper" and click OK to close this window
5. Restart your PC and try to use RealPlayer again
If the issue persists, please let us know.