On may 10th of 1940, the day that Fall Gelb started the 7th Panzer division was comprised of the:

25th Panzer Regiment

The 7th Rifle Brigade

and the 78th Artillery regiment

This is in addition to the various support brigades, regiments and battalions; like supply battalions, signal callers, and reconnaissance battalions.

Now the 25th Panzer regiment contained 34 Panzer I tanks, 68 Panzer II tanks, 91 Panzer 38t tanks (produced in Czechoslovakia), 24 Panzer IV tanks, and 8 Panzer Bef 38t tanks (these were also of Czech origin).

You might enjoy this page:

http://www.lexikon-der-wehrmacht.de/Gliederungen/Panzerdivisionen/7PD-R.htm