It looks like a remnant of a malware. Download CCleaner (
http://www.filehippo.com/download_ccleaner/ )and install it. Run CCleaner, and click "Options" tab and click on "Advanced". Here, uncheck the option "Only delete files in Windows temp folders older than 48 hours". Next, go to "Cleaner" tab and click on "Run Cleaner". This will remove all junk and temp files. Once this is done, go to "Registry" tab and click "Scan for Issues". Once it completes scanning, click "Fix selected issues" to remove all invalid Registry entries.
Next, download Malwarebytes Anti-Malware (
http://www.malwarebytes.org/mbam.php ) and install it. Reboot the PC into safe mode and run Malwarebytes. Go to the "Scanner" tab and select the option "Perform full scan" and click "Scan" button.
Once all the above steps are done, post back if Malwarebytes detected anything and also if the "rul dll error" still exists.