Websites not completely loading

I've got a fairly new Dell Inspiron ONE computer with Window 7. Every since I bought it new some website home pages intermittently will not load completely. Sometimes I can refresh the page and it will open. I keep the cookies along with defragging on a regular basis. After clearing cookies I can sometime reboot and the websites will load ok. Also sometimes the page may continue to load and sometime it will stop loading and only the website header will appear. Some days I can go all day and all website will load ok. What's going on here?

Can and does my ISP have anything to do with these conditions and or is there anything I can do to correct it?

1. Try resetting the DNS Cache and restore the hosts file:

"Flush the DNS cache and restore MS's Hosts file ...
Copy and paste these lines in Note pad.

@Echo on
pushd\windows\system32\drivers\etc
attrib -h -s -r hosts
echo 127.0.0.1 localhost>HOSTS
attrib +r +h +s hosts
popd
ipconfig /release
ipconfig /renew
ipconfig /flushdns
netsh winsock reset all
netsh int ip reset all
shutdown -r -t 1
del %0

Save as flush.bat to your desktop. Right click on the flush.bat file to run it as Administrator. Your computer will reboot itself."

From Post #5:
Detected DNS cache poisoning attack.

2. Reset and turn off the router for 5 minutes

3. Look into your Wireless Network Configuration.

4. Replace your Wireless Card

5. Call your ISP.