xDSL modem annoyances

Hello, I am sort of new to the board, and my question isn't mine this is for my friend, he uses WinXP with "permanent" connection through ADSL with static IP, the problem is under permanent in quotes - every once in a while his connection is no longer permanent, but all lights on modem are indicating that it is, the ipconfig reports the that everything is intact, but the simple ping to yahoo timeouts with 100% packet loss, in order to get back online he must restart modem. I am pretty sure this isn't modem or NIC or any other hardware related problem - we tried it on different setups to the same result - after a day his connection expires, plus I brought my little linux box over his place and it stayed up for 3 days w/o restart, reboot, you name it, then I just got it back, so ISP isn't the problem either. I believe it is TCP/IP stack related. Can any of you, windows gurus, give me an insight or a slightest idea what it could be?
Thanks

 

Disable Hibernation. Disable the Windows Messenger Service. Disable the DNS Cache Service.

 

In addition to the items brett listed:

Check the event logs for error or warning entries that look "networkish ".

Stop & disable browser service.

If his address is "static" as in the ISP assigned a specific address to him for ever, stop & disable DHCP service.

And if it hangs again, try pinging 127.0.0.1 just to wake the NIC up. Not sure exactly why but this sometimes helps.

If none of brett's or my suggestions help, post back. There are other items (a few obscure registry settings) that can be changed and might help.

 

Thank you guys, I'll look forward to following your suggestions, AFAIK DHCP isn't running, you brought up a hibernation issue I'll disable APM and screensaver, and I'll post my progress soon.

 

Well, APM and screensaver were disabled all the time, so this is a miss. I think I'll give it up, anyway it isn't my problem and I ran out of suggestions. Thanks.