I have many suggestions for you. First uninstall all the Asus crap that came with the computer - it seems to me you have already done that. If you're wondering what svchost is, you can check out here:
Find out which services are hogging your computer’s resources | Vista Rewired
2) Your hard drive is always spinning? It could possibly be the indexing service that you may not need. To disable index do the following:
Open My Computer. Right click a drive and choose Properties. Then at the bottom where it says Index this drive for faster searching, uncheck that box.
3) Slow startup?
Disable programs from running at startup | Vista Rewired
If you have anything else, feel free to visit my site or ask me here. Good luck.