I have disabled the windows firewall with the same results.
"We were unable to verify the Service Tag or Express Service Code you have entered. Please verify your entry or choose one of the options to the right. If you recently purchased a system, please try again in 48 hours."
So it’s certainly doing “something” here.
Is it possible you installed an add-on like NoScript or other anti-malware?
If you suspect the router (which seems highly unlikely), try connecting one of the troublesome PCs directly to the modem.
"Is it possible you installed an add-on like NoScript or other anti-malware?"
Not likely, three of the four PCs have fresh installs of windows. Why would safari work on the macbook, but not chrome? Something else is going on .. it's been a mystery since I first bought my Alienware Aurora R3. At first, I thought only the alienware was affected. Then I realized it was every computer on my network.
I'll try that. Sorry, I must have overlooked you suggesting it. For the record, I've had 3 different wireless routers since the problem started.. It's highly unusual if all 3 wireless routers would be introducing this issue.. But I'll give it a shot and bypass the newest one.
Confirmed. It still happens while connected directly to the cable modem. In fact, I called my ISP, and the gentleman I was escalated to found that it happened intermittently on his side as well between multiple browsers. I think this takes me back to my initial assessment that it is Dell's website and coding.