Ultra-Thin

[TrueBlue11]

I've tried everything, resetting to factory settings using the windows 8 recovery dvd seemed to have slowed it down. Mkv videos lag, StarCraft 2 lags (it was fine before), and even just browsing the internet for a while slows it down.

I have tried

Minimizing the effects used by Windows 8

Updating drivers

Optimizing Software

Anti-virus and anti-malware

still, nothing... 

[vvprad]

Try updating the video driver from Acer website 

Click on the above link, select Search by Product Model then enter the model number. Select the OS as Windows 8 and find the video driver and download the same and install it.