Problem loading Web pages and downloading

Hello: D
I have a problem to download and upload web pages, I do not know where it may come because it happened all at once and it does on 2 pc (in vista but I had a sub and xp same result) and even Ethernet. The technician Numeric able tried with his computer and it works , my question is how to solve my problem.
- Impossible to download, either on Firefox or Internet Explorer: it stops in the middle and makes me an error message on some site, saying that the connection was closed by the server.
- At loading Web pages is very long and at the start of the PC, it often takes to reach that actualizes to display the entire page.
As against a search on Google poses no problem and the results appear quickly.

kaspersky not good and norton

norton symantec.com

Are you directly connected to your cable modem or you have a switch or a wireless router?

It is a modem router (Netgear WGR614) through which the phone and internet. Here I am wifi but I tried ethernet and the pages are too long to load and download same problem.
It seems that the computer (no matter which of the two) trying very hard with the site or download the file to whether Tournament, net, or others.

Thinking it was a router problem as it did on 3 computer (before I sell it in XP), the technician finally come and this is something that was plugged in ethernet and had no problems downloading or load a page an "old computer" for win xp. He even said that the problem had vista, the problem is that the computer was third in XP and even reformatted, it did not work.

Thank you for your advice and suggestions