Since 30th October 2013 there have been many reports of an error when starting Photoshop. The error states file MSVCP110.DLL is missing. When you click OK on this error it keeps popping up, and after 10-15 clicks of OK, photoshop will start.
This error ONLY OCCURS if you have Nik Software filters installed! Recently google, who own Nik Software, pushed an update out to all users, this update caused the error to occur.
The zip file attached to this post, includes the msvcp110.dll file and a readme.txt file on how to place the dll file in the required folders to resolve this issue, if it is occurring for you.