I have WD MyCloud that F-Secure don't like

I just purchased WD MyCloud backup system (external) & it's taken a week to try and find out why WD Smartware once downloaded firstime recognises my system drive & backs it up. However though, as soon as pc is off overnight & switched back on in the morning WD Smartware fails to notice my C drive for continous back-up after a whole week un-installing & re-installing WD Smartware the same thing happens everytime. it works first time then after Pc is off & back on again, it fails to notice my pc's drive. Anyway, I decided to turn off F-secure temp. & nothing. But, then I found that if you uninstall F-secure Completely & re-install WD Smartware. it works ok as usual first time. So I shut down Pc as usual & hey presto, after re-booting my WD Smartware now always works & recognises my Back-up drive always. Clearly this is something to do with F-Secure preventing Back-up to my Network MyCloud from working. Why is this? I am to afraid to re-install F-secure as this is the problem & I don't know how to deal with it. I pay each yr for this service & it's a shame to lose it. There must be a way around this