My new network setup. Need help!

[NeedForHelp]

Sirs and Madams
Here's my new network setup, I have manage to replace the ISP supplied router with my old prolink hurricane 9000p which have 4 LAN ports.

                                       Internet
                                         |
                                       Prolink
                                       | | | |______ laptopXP
                     laptopXP _________| | |________ laptopVista
                                         |
                                         |
                                       PCXP

These are some my router's settings:               Workstations:
1. Virtual Circuit: Enabled                               1. Obtain IP auto
2. Bridge: Enabled                                         2. Obtain DNS auto
3. IGMP: Disabled                                         
4. Encapsulation: 1483 Bridge IP LLC                When I'm connected to the
5. VPI/VCI: 0/100                                         Internet:
6. Service Category: UBR                               1. My workstations IP starts
5. DHCP: Disabled                                             with 122.2.xxx.xxx
6. Pool: greyed                                            2. My gateway is 122.2.xxx
7. DNS Proxy: Enabled                                   3. I don't know my WAN IP
8. LAN IP: 192.168.1.1

Note: I don't know what these settings are, I have just followed a mixture
        of tutorials and manuals. I don't know what my workstations WAN IP's are but
        they say I should only have one WAN IP for my workstations and the "Mods" 
        here can see it.

Problems:
1. The PCXP's connection is unstable. Although the connection icon in the
    system tray says the PC is connected, I can no longer browse the net and
    the laptops in the network. It happens from time to time (15-20mins interval).
    What I did, was to disable the LAN connection and enable it again and the PC
    gets connected in the net again.
2. The three laptops seems OK though, they never got disconnected.

The medecine I gave to my PC:
1. I formatted the PC and installed only the necessary drivers and softwares.
2. I tried connecting again but the problem is still there.
3. I don't know why.
4. Please help.

[YeOldeStonecat]

It's a matter of knowing what kind of connection your ISP requires your equipment to be configured for. Bridged DSL, PPPoA DSL, or the more common...PPPoE DSL.

DHCP appears to be disabled...so workstations will not pickup their correct TCP settings that way.

Is there a reason you want to use this router, over the ISP supplied one?

[NeedForHelp]

Yup, this router has four ports for LAN connection while the ISP supplied one has only one (its just for one computer), I think its newer though.

I'll try enabling DHCP... thanks very much.

[nagetech]

You need to make sure:

1. The router is acutally picking up ISP provided IP Address/subnet/gateway/dns

2. Computers on your network are setup for DHCP, and there are no conflicting addresses.

3. The router itself is setup as an internet DHCP server.

Let me know if any of this helps!