Hello Peter,
If this is the same Windows 7 that you used the
Windows 8 Upgrade Assistant to qualify for an upgrade copy of Windows 8, then you are no longer allowed by the
EULA (see below) to use the product key for this Windows 7 when you have the upgrade copy of Windows 8 installed.
If you wish to use both, then you would need to buy a "system builder" copy of Windows 8 instead.

Note
MICROSOFT SOFTWARE LICENSE AGREEMENT
Windows 8 EULA
What about upgrading the software?
The software covered by this agreement is an upgrade to your existing operating system software, so the upgrade replaces the original software that you are upgrading.
You do not retain any rights to the original software after you have upgraded and you may not continue to use it or transfer it in any way. This agreement governs your rights to use the upgrade software and replaces the agreement for the software from which you upgraded. After you complete your upgrade, additional software will be required to playback or record certain types of media, including DVDs.
With that said above, your data on the Windows 7 partition will remain intact. You would only be shrinking that partition. If you like, please post a
screenshot of your Disk Management window showing your full HDD layout. This way we can take a look at it to see if you may need to do anything else.
Partition or Volume - Shrink Partition or Volume - Create New
I agree with Rich above. 22GB is way to small for a Windows installation. You would be better off with at least 60GB.
Hope this helps,

Shawn