I store a lot of my content in TrueCrypt volumes. I end up mounting these volumes many times during the week, when I need to access some files. Most of these times, I need read-only access to the volume. I rarely need to add or modify files to this volume. To prevent myself (or Windows) from making changes to the files in this volume, I use the read-only mount feature in TrueCrypt.
To turn on this feature by default for all mounting of TrueCrypt volumes, go to Settings → Preferences and select Mount volumes as read-only. After this, all TrueCrypt volumes will be mounted as read-only partitions.
On the rare occasions when you need to mount a TrueCrypt with write access, choose the Mount Options in the Mount dialog and uncheck the Mount volume as read-only option. This unchecking affects only this mount, volume mounts will still remain read-only by default.
Tried with: TrueCrypt 7.1