A few other things to try:
1) Update your drivers (Bios, graphics card,etc.)
2) defrag your system (click on start, programs, accessories, system tools, disk defragmenter).
3) click crtl, alt, del and close all programms except systray and explorer
Open an internet site,
at the top left
click tools
click internet options
click the connections tab
now look for 'never dial a connection'
and click the small cirlce next to it