|are these the SAME websites that won't load?|
If the answer is "no" then it's almost certainly an issue with the Internet access the I.S.P. is providing.
Often peak times (e.g. when kids get home from school) cause problems.
You could try looking at this setting:
And when you can't access a page, hit CTL + F5 (this will clear the cache and reload)
Also check what speed your Internet connection is. You can hover the mouse pointer over the tray icon of the 2 computers. Both dial-up and DSL access are subject to fluctuations in speed depending on how busy the lines are.
"If we don't succeed, we run the risk of failure." - BILL CLINTON