Halion sonic 3 will not open

Ive had HS3 installed for a few months and everything worked fine. Well I decided to download the update via download assistant and install it. After installing it HS3 no longer wants to open, literaly nothing happends. Trying to load the vst in Reaper causes reaper to hang then immediatly close. HS3 is authorised and shows up in my elicenser. Also steinberg library manager will not open. Its as if my computer isnt allowing the apps to open. Any help or advice would be gratefully appreciated. Reaper 5.9/ Windows 8.