Before I begin, I know what you are thinking. If you want your Truecrypt volume to be mounted without a password, why even have an encrypted Truecrypt volume? It doesn't sound very secure.
You are right, and that would be a valid question. I would say that you should only use this on computers that are protected with full disk encryption already. If you don't use full disk encryption, typing your password in once to mount a volume isn't going to kill you.
So let's say that you have full disk encryption configured already, so auto-mounting non-system Truecrypt volumes automatically isn't a huge security concern for you. Well there are two ways of doing it depending on if your non-system Truecrypt volume uses the same password/keyfiles as your system encrypted drive or not.
Let's say your non system drives use the same password/keyfiles as your system drive, here is what you need to do:
- First open up Trucrypt and go to System > Settings
- Check the box that says Cache pre-boot authentication password in driver memory
- Click OK
- Next mount your non-system volume(s) that you want auto-mounted at logon
- Select the mounted volume, right-click your mouse and select Add to Favorites
- Now go into Favorites > Organize Favorite Volumes
- Select your Favorite Volume(s) and check the box to Mount selected volume upon logon
cd "C:\Program Files\TrueCrypt"
truecrypt /a favorites /v PATH TO YOUR TRUECRYPT VOLUME /p PASSWORD /q