While normally Windows 7 Backup & Restore won't let you pick what goes into the System Image, there is actually a way to force it to exclude specific volumes if you are certain that they are non-critical, though the method is a bit crude:
Dismount the volume
You can dismount internal mount points by removing their drive letter. This makes Backup & Restore unable to see them, and it will ignore them when creating System Images. Generally though, removing even non-Windows volumes that are in use by the system is a Bad Idea™, so do so at your own risk. You may crash or corrupt Windows and/or anything currently accessing the target volume depending on the files stored, or the System Image may not be usable to boot from.
First, some sanity checks are recommended to make sure you don't lose data or the OS due to simple problems:
- Ensure swap (virtual memory) is disabled for the excluded volume
- Ensure that important programs aren't using the excluded volume (it can be helpful to do the dismount from a cold boot due to this reason)
Now, to dismount the volume that you want to exclude:
- Right click your taskbar Windows button, and select "Disk Management" (or Win-R and execute
diskmgmt.msc. Both requires Administrator)
- Right click on the volume to be excluded, and select "
Change Drive Letter and Paths"
- Select "
Remove"
- If a warning pops up regarding drive letter change, select "
Yes"
- If prompted that the volume is currently in use, press "
Yes" (in this case you may want to double check sanity checks before proceeding)
- The volume should be dismounted. Note that programs which were accessing the volume may crash.
- Open Backup & Restore (Windows 7) from Control Panel
- Select "
Change Settings" (requires Administrator)
- Follow the wizard to create backup settings. The unmounted volume should no longer be included when you create the System Image.
Once a backup is running, you can remount the volume:
- Go back to Disk Management
- Right click on the volume to be excluded, and select "
Change Drive Letter and Paths"
- Select "
Add"
- Pick the previously used drive letter (it should default to whatever was used before, such as D)
- Select "
OK"
- The volume should be mounted again and usable.