Can't launch apps once connected to internet

[Newbie]

I have seen this EXACT problem referenced in Linux newsgroups, but I am on
XP.

New box, factory-installed Windows XP Pro, Office XP Pro, got all the
updates for both.

On bootup, everything fine. Once I use my dialup (AT&T Worldnet) to
connect to Internet, as soon as the connection is made, I can't launch
ANY applications. Dbl-clicking icons on desktop starts little
hourglass, hourglass goes away after about 4 seconds, no app opens.
Same when trying to launch from Start->Programs. Cntrl-Alt-Del does
same thing, shows little hourglass, but the process/app/resource box
doesn't come up. NO application of any kind can be started.

Worthy of note:

- Any application that I started BEFORE dialing up continues to run
fine once online, just can't open NEW ones.
- This problem is very specifically described in the Linux newsgroups,
and the solution is apparently to set KPPP (whatever that is) option
"Autoconfigure Hostname from IP" to NO (uncheck). I have no idea what
equivalent this would be in Windows XP, except for maybe "obtain IP
address automatically" in the TCP/IP properties, but this needs to be
set to YES, I think, because of the nature of ISP's (I could be wrong
here)

Please please please help, this problem is insane, this is a brand
spanking new system, and I can't believe I'm having these kinds of
problems so early in the game. AT & T, surprise surprise, is of NO help

Any help is greatly appreciated, and thanks.

Newbie Supreme

 

[roger]

Hi Newbie,

Are you using XP's firewall or a third-party one?
If you're using a third-party firewall, try disabling this and
enabling XP's native firewall instead.

The setting 'Obtain IP address automatically' must be on (I have it so
on my dial up) below this there is a box where you enter the DNS
addresses of your ISP. Have you configured this box using the values
provided by your ISP?

Good luck