Boot Camp: Alt-Tab Lag Issues

I've been experiencing serious lagging issues when minimizing full screen applications to the desktop/internet browser. This might seem like a normal situation with many computers, but I am running the high-end iMac so it doesn't seem like I should be experiencing this. Anyone else have this problem or know of a solution?

I've tried the usual tricks and they don't seem to be working (defragmenting, anti virus/adware/malware scans).