How to get rid of boot options?

How do I get my virtual machine to work fast? I've enabled hyper-threading in boot options, but even then, there is no difference.

• When I first enabled Hyper threading, the virtual machine I had(Ubuntu 12.04) became very fast until I installed another virtual machine beside it(Ubuntu 14.04). After installing 14.04, the first one reverted back to being slow. I removed the second one, even then it isn't getting fast. How do I get it to become fast? I use Virtual box. By fast, I mean it occupies the whole screen in full screen mode and seamless mode is available. My default OS is Windows 8

• Answer:

  One good way to speed up linux is to decrease swappiness to a value less than 10 (default:60) and to install prefetch. Download and install compizconfig settings manager and lower the graphics. Compiz is a ram hogger,literally. I found my system speeding up by atleast 70% after I slowed compiz down. And since you're running a VM machine, make sure you dont run too many applications in the background which put extra load on your resources. And every time after you remove a system, make sure you clean and defragment your drive to remove any traces of the old files.