Hey I managed to get it working here is how:
Go to the location of your ADB USB driver which you can find in your_sdk_path\usb_driver. (ex. C:\Program Files\android-sdk-windows\usb_driver)
Open up: android_winusb.inf.
Now if your on a 32 bit install of XP scroll down to the section labled [Google.NTx86], if you're on a 64-bit system scroll down to the [Google.NTamd64] section. In that that section paste in:
; HTC Incredible
%CompositeAdbInterface% = USB_Install, USB\VID_0BB4&PID_0C9E&MI_01
Now save the file.
Now if you plugin in the device and select that directory to install the USB driver from to install it should work. Finally go to your_sdk_path\tools. (ex. C:\Program Files\android-sdk-windows\tools) and run adb kill-server, and then adb start-server. When the server has started run adb devices and your incredible should show up.