I am having a problem on my Windows 8 64bit (legitimate) computer. I've got all the drivers for my motherboard, and in the last few weeks I have realised that smss.exe is using up to 40% (average of 30%) of my CPU. When it starts doing this, it can cause crazy lag in my games, even though I have a very high-spec PC.
The file is located in system32 and I've ran lots of AV scans (from Microsoft defender and MalwareBytes). In addition to this, I've also scanned for disk errors on all drives, and replaced the smss.exe from a working PC, but the problem still occurs.
A system restore is not an option here.
If there is no solution, is there any possible way to force the priority of the process to low so my games are playable please? At present, the process cannot be terminated, or edited at all - even the affinity.