Thanks for the quick response. Yeah, I did repair the vcredist for both x86 and x64, but the problem remains the same. I'm not sure about video drivers (sorry - I'm not particularly computer literate). My graphics card is the Nvidia GeForce GT755m, and I'm using the most up to date driver (version 388.71) which was released 2017.12.20. I did follow the instructions for uninstalling this driver, restarting my PC, then downloading the driver again, but it still didn't work. Would reverting to the previous driver work? (not sure how I would do that, but could find out!)