[lafroste]

Can you still ping the ISP from the Router after the 12 hours?

No, I cannot ping even the router after 12 hours. To earlier questions:

Yes, it had been more or less permanent in the past, persisting sometimes for weeks.

ipconfig/release, ipconfig/renew do not work after expiry, generating a "DHCP server unreachable" error message.

Both PCs have static IP addresses that I configured.

[tacticalogic]

Both PCs have static IP addresses that I configured

If you have static IP's, then release/renew aren't going to help. It sounds like it's the router's dhcp lease that's expiring and needs to be renwed.

[milestogo]

Check the "data" light on your cable modem. If it blinks, you are probably connected to your ISP.

Both PCs have static IP addresses that I configured.

Change the setting to receive an IP address dynamically. Once you are back online, run ipconfig /all and check the "lease expires" time.

Lease Obtained. . . . . . . . . . : Sunday, March 07, 2004 9:36:13 AM

Lease Expires . . . . . . . . . . : Wednesday, March 10, 2004 9:36:13 AM