There are many reasons why such messages may be generated and one of them could be malware.
To help you and prescribe the remedy, I must make a diagnostic and to do so, I require a report.
1. Open this link and download ZHPDiag2 :
https://nicolascoolman.eu (Don't be alarmed is the site is in French, it sometimes happens, the tool will take your system language and allow the download if you get a warning message, ignore it.) Click on the download button
2. Save the file on your Desktop.
3. Double click on ZHPDiag.exe and follow the installation instructions.
(For Vista, Win 7 and 8 users, click right to ensure you execute with admin right)
4. Double click on the short cut ZHPDiag on your Destktop.