Driver problem

I just got a Mega 2560 for a project. I plugged it in and windows could not find driver. I searched this site and found that the driver was in arduino-022/ drivers. I loaded this driver and it worked. When I went back to an older project on a Duemilanove. It was no longer found by the windows xp computer. I am not sure why this was lost but I cannot figure out where this driver went and can not find another. How do I make both work at the same time?

Jim

It was no longer found by the windows xp computer.

Does the computer make the "device insertion" sound when you connect the Duemilanove?

alfiesty:
When I went back to an older project on a Duemilanove. It was no longer found by the windows xp computer.

The Duemilanove used a FTDI chip. Do you have the FTDI drivers installed?

I reloaded the drivers with ones I got from off the Internet and things are now working. I am not going to connect the Mega2560 again until I have to other project finished!
Jim

alfiesty:
I reloaded the drivers with ones I got from off the Internet and things are now working. I am not going to connect the Mega2560 again until I have to other project finished!

From a driver point of view, the Meg2560 and Duemilanove have nothing in common.