How do i get my WPA if i lost my manual for the RCA DCM425

I would suggest that you go through this guide, it will explain you every step which you need to make to get your modem and internet connection back on track:
The ultimate Link Troubleshoot guide: Problems. solutions, PDF manuals

not sure really, but you may be able to further investigating here
www.cablemodems.com/downloads/specsheets/RCA DCM425 Digital Cable Modem.pdf

You can download drivers for the Thompson RCA DCM425 here

It could be Mediacom having problems if not unplug your rca dcm425 for 30 secs and plug it back in im sure you hear people say that alot but it works and if you have a router unplug it first plug it back in and then the rca.

Cable Modem Troubleshooting RCA DCM425
or
You can change the radio channel on your AirPort Extreme using the AirPort Utility, as follows:

• Run the AirPort Utility.
• Select the AirPort Extreme, and then, select Edit.
• Select the Wireless tab.
• Select Wireless Options.
• By default, the channels for both the 2.4 & 5 GHz radios are set to "Automatic." You would first change this to "Manual," and then, select the desired channel.

RCA DCM425 digital cable modems only have one Ethernet cable located in the back of the device. In order to have two computers connected at the same time you will need to have router. The router will connect to the Ethernet port on the back of the RCA modem and then you can have up to 4 computers connected directly to the router using Ethernet cables. If any of your computers are wifi compatible they will also be able to get online by using the wifi from the router.

Hello Friend,
If you didn't change anything in modem side, that means the modem is still connected to internet. in this case you can connect the modem to your computer via the Ethernet cable. with this cable you will not need to install anything on your computer, just plug the Ethernet cable to the RJ45 port and start browsing internet.
The only case when you will need the drivers is when you want to connect the modem to your PC via USB cable.
Here is a link where you can find everything about your modem: quick guide, user manual, usb drivers ...
Best Regards,

Contact your cable provider, you most likely have a signal issue related to poorly seated fittings, outdated or wrong bandwidth splitters, or low signal from outside feed. Quadshield rg6 is the best indoor residential application though. -Comcast tech

Try this site - they have RCA425 USB drivers posted
http://helpdesk.powergate.ca/index.php?id=19

Took a while but i think i got the usb driver for you :-) http://helpdesk.powergate.ca/index.php?id=19 Hope it helps mate.. John