I have 2 windows boxes hooked up via ethernet cards and using shared folders. When the machines are connected to the Internet via dial-up, are the folders visible to others across the 'net?

Another question,
the 2 machines are using static assigned IP addresses,
is it possible that the ip will clash with another when the machine is dialed-in to the net? for that matter, which datalink interface does the system know to use?

Just for you and my own curiosity, I asked one of my companies network admins about this.

Yes, if someone hacked your PC, then they would be able to see and work with your networked drives. Also, any computer attached to it could be vulnerable as well.

Now I am not completely sure, but as long as each machine has a unique IP address assigned, they should not clash.

The answer to this question is simply yes.

Windows comes with tools to view remote shares, goto dos prompt a type net view \\host.

heres what happens when i do it inside my network,

This is, however not a security flaw, because passwords and levels of security should be set before going onto the internet. For some commands on howto use net.exe , goto a dos prompt and type net help, and you'll see the commands you can issue. You might want to disable netbios as your ip can be added to an attackers lmhosts.sam, and they can just browse your computer by using their find files in their start menu, they could also print to your shared printer. From loging onto your machine, they can also view shared drives inside your network. Get a firewall, hardware or software..it doesn't matter too much, as long as you can filter the ports/ips etc to your liking.

Anyway, i'm babling on a bit now, i best shutup.

2)sorry cant help.

YES - they can ! They can write to and delete from them as well. Windows has almost No security with shared folders or net services.
NT/2000 has "Remote Registry" running by default. Shared folders are the EASIEST exploit on the web. That is the reason "Code Red" and "nimdA" present such a security risk. They enabled Guest logins, set their priveldge to "Administrator" and unset the password for the account.
Right click on Network Neighborhood (from Windows Desktop) select properties and then unbind "File and Printer sharing" for your dial up connection. You might even be able to get away with unbinding "netbios" from tcp/ip on the dial up too. but if you arent able to connect to the net your ISP is requiring it to verify you on their network. You might do a little reading on http://grc.com about this very subject. He has very good detailed instructions about unbinding these protocols from your net connection. Dont forget to turn off "Universal Plug and Play". It is an active server on port udp port 1900 and TCPIP port 5000. Run "netstat -a -n 20" in a dos window and see what shows.
MAKE CERTAIN that you do not unbind TCPIP from your net conection or you will not connect at all.

That's why you should always assign your machines local IPs (for example 192.168.1.x). Then there will be no problem.