Hi Peter,
Windows 7 reached official end of life January 2015. That means you no longer receive Microsoft patches for security updates and protection for your PC from malicious attacks. How can you say for sure your system has not been compromised, and that an attack of some kind is not affecting you? An antivirus program alone is not adequate. [Or perhaps you have extended support arrangement until 2020?]
I am not going to make the usual comment about why don't you upgrade, but you are running without safety belts now.
And yet another dreary query, why not the latest 2.19 version, currently 2.19.81? 52 seems a rather arbitrary release to be sitting at. Just my usual suggestion, based on my excellent experience of the remarkable stability in general of the development luine.
Andrew