Every other reboot, my Dial Up network connections disapppear, but my LAN or High Speed Internet Connections remain there.

Even though the connections are not visible once connected (no icon shows up in the System Tray and no successfully connected balloon pops up) and not visible in Network Connections, the connections are still there, because if I use the connection program that came with my Modem, then the connection is still made but invisible.

I wouldn't really bother about this, because it doesn't cause me any problems, but because the connection isn't visible, the PC upstairs that connects to the net through this cannot access the net.

Does anybody know why this is happening because sometimes they are there and other times they are not.

I thought you were on broadband.

I am, but the connection is listed under Dial Up.

Did this just start happening? etc.

I see alot of network issues re: SP2's firewall...
Also what about the Modems' Software? Any settings or options there?

Have you checked the Troubleshooting tab under Network Connections? Or the Tools?

Does it make a difference which computers are connected or not while you are connecting this machine? (hope that makes sence)

Is it precisely every other boot? Do you notice any other changes?

Do you notice anything in your Event Viewer?

& just to clarify: the "upstairs pc" relies on the "downstairs pc" to connect to the net?

Also found this in the knowledge base fwiw:

Network and Dial-Up Connection Icons Disappear When You Use Dcomcnfg.exe to Set the Default Impersonation Level to Anonymous

Yes his downstairs pc is the host........ they are connected via ethernet cable.

No options in the modem software. Its an Alcatel SpeedTouch USB 330.

I'd tried the troubleshooter and its useless.

Its just two machines. This one being the host. Its turned on first, then connected to the net and then the other one is turned on and works fine when the connection is visible.

The article you posted is for Windows 2000. Its the computer upstairs that is 2000 and thats not where the problem is, its this computer, the XP one.

The Windows firewall is off, I use Sygate. Sygate is configured fine.

All Windows Updates are in place obviously.

I cannot say that its every other reboot exactly. Because sometimes after 2 reboots its fine but on the third, disappeared. And then it can sometimes take 1 or 2 reboots to get it back. They've been working fine for a couple of days now, but I've only had 2 reboots.

As for Event Viewer, I'll check that next time they disappear.

Under Admin Tools > Services > Network Connections
See that this service is running & set to manual or automatic;
As well as its' dependencies.
This sevice depends on Remote Proceedure Call (RPC).

See if there is a difference the next time the connection vanishes.

Also perhaps run this while everything is ok:

Save Settings on Exit (Line 54)
http://www.kellys-korner-xp.com/xp_tweaks.htm

Jephree, thanks for your help on this and sorry I haven't responded sooner. I found a Microsoft Article about the problem today and I've rebooted a couple of times and all seems fine. Lets hope it lasts. Thanks again.

The Microsoft Article is here: http://support.microsoft.com/?kbid=825826