To perform a clean installation of RealArcade, you'll need to uninstall it and delete its directory. You can then reinstall (redownload) it.
To uninstall RealArcade:
1. Click the Windows Start button and point to Settings, then Control Panel (In Windows XP: Start > Control Panel ).
2. Click Add or Remove Programs.
3. Find and select RealArcade from the list of programs.
4. Click the Change/Remove button.
5. Follow the on-screen prompts.
6. When asked if you want to remove the files, choose Yes.
To delete the directory where the RealArcade was installed:
1. On your computer desktop, double-click the My Computer icon.
2. Double-click the C: drive.
3. Double-click the Program Files folder.
4. Double-click the Real folder.
5. Right-click the RealArcade folder, then choose Delete from the menu.
To reinstall RealArcade:
Go to www.realarcade.com and download it again. This should eliminate the errors you were receiving.
Note: RealArcade must be downloaded to the Local C: drive.
If you are redirected to the RealArcade Game Guide page when you enter this URL in your browser, scroll to the bottom of the page:

You should be able to manually re-install RealArcade via the Re-Install RealArcade text link, located in the lower-right corner of the screen.
Note: Reinstalling RealArcade will not affect the games you already have installed.