How do i make my computer run faster?

My laptop, an asus u50a, suddenly got extremely slow today after working perfectly fine yesterday. I've already done many things mentioned here or elsewhere online. I deleted all my internet history and cookies. I downloaded easycleaner to clean up my registry. I uninstalled about 30 different programs i don't use. I used system restore to restore it back to a few days ago. The computer works well for 2 or 3 minutes after turning it on but then starts sporatically freezing, which usually happens when i open up the internet browser. After browsing through a page or two it would freeze up and say that the shockwave plug-in has crashed and it stops the scripts from shockwave, but keeps freezing up so i tried using ie, firrfox, and chrome but none of them worked so i uninstalled them then downloaded them on another computer to a usb and reinstalled it on here but it still didn't work. It freezes up on its own actually when im doing absolutely nothing on it as well. I tried creating a new user on the computer but that didn't work. The computer is only a year old and worked smoothly until today. All the changes I've done i did in safe mode because.that's the only way it doesn't freeze while im making the changes. Please give me somewhere else i could start to try to fix this issue. I've spent literally the last 6 hours nonstop trying to fix it and its only gotten marginally better at best.