What version of Internet Explorer? If it is version 6, then upgrade to 7 or 8.

It is quite possibly a DNS problem. First, install Google Chrome or another browser and try again - this is the easiest thing to try. If you have the same problem it is most likely a DNS issue. DNS (domain name service) is the service that translates web addresses into numbers - IP addresses.

Next, go to your Network Settings and see if a specific DNS server is utilized. right click on My Network Places, right click on LAN or Local Area Network (assuming you have a home network), Select Internet Protocol (do not uncheck the checkbox - click on the words), then click Properties. If "Obtain DNS Server Address Automatically" is selected, then the DNS is determined by your internet provider. If "Use the following DNS Server Addresses" is selected, then you are using hardcoded dns servers. If you have to do that, OpenDNS is very good.

If you have a DNS server hardcoded, write it down (always write things down!), then select Obtain DNS Server Address Automatically" and see if the problem goes away. If it does not go away, you can try OpenDNS by putting those addresses in your dns setting (go to their website, sign up for free and they tell you the IP addresses for their DNS). Enter those into the "Use the following DNS server addresses".

Finally, it may be your internet provider's DNS blocking these sites. Contact their support and see what they say. I have run into this in the past. depending on how you get your internet, it could involve multiple parties. It is hard to pinpoint the problem without seeing your laptop.

As mentioned previously, it could be other problems. Malwarebytes is a great program for deteecting and removing malware. I really don't think a complete reinstall is the answer, as that is usually the last resort for fixing a problem.