Hey Playtime,To help speed up teamviewer there a simple way to do this.
On their computer you working on,Go to Start>Right click (My/Computer)>Properties>Advance System Settings> Performance Settings> And choose Adjust to Best performance.and Click Apply.
This will make closing and opening items on their side almost instant.
I use teamviewer alot while helping friends or new players to denagle their computer.
To offer them a more enjoyable game time.
Also,This will let your computer load up windows/programs ALOT faster then it was with Windows choosing whats best.