Why does my internet connection fail intermittently?

Solution 1:

The university of Berkeley has a website that will analyze all sorts of aspects of your Internet connection such as DNS, ports, upload/download speed etc. It will report anomalies to you. It is here:

http://n1.netalyzr.icsi.berkeley.edu/

Solution 2:

It sounds a lot like a DNS problem, considering downloads do not drop out and it only affects one laptop on the same wirless network.

I would try different DNS servers.

I had a similar problem once and it turned out to be that my ISP's DNS servers were crappy (but that affected everybody on my network).