Internet explorer 8 cannot display web page--ERROR MESSAGE

Two computers, a Dell Inspiron 530 (has direct hardwire connection) and Toshiba laptop (wireless connect) were working well on home network--both Vista Home version.

Kept getting ERROR MESSAGE "Internet Explorer cannot display the webpage" on the laptop, so thought it might be router, since sometimes could turn it off/on, then the network was there & working. Router was Linksys wireless G-2.4GHz.

Bought Belkin "N" wireless router. Was online with competent Belkin tech support who helped with install of network and ended up saying the router works fine (he pinged) and the problem is Windows or McAfee firewall will not let the signal to computer.

When I run diagnostic, it says "Network diagnostics pinged the host but did not receive a response." It shows that the network is there, strength of signal is excellent, but still no hook-up to the laptop.

The desktop works fine with no connection issues and all the "blue" lights show the Belkin is working fine.

Belkin tech says turn off Windows and/or McAfee firewalls.

What do the LEARNED folks here suggest?

Thanks,
DJ