Got it sorted. If anyone ever comes across the same problem, what I did was run System File Checker:
"sfc.exe /scannow" from an elevated DOS prompt
This repaired a few files, such as DWrite.dll, d2d1.dll, d3d10core.dll, XpsGdiConverter.dll and a few more.The files it repaired were all related to graphics (Direct2D, Direct3D and GDI). Looks like an update for either Windows or DirectX must have gone wrong.