Windows 7 check CD driver where it was installed

[#1]

Updated computer - well full rebuild - new motherboard, CPU and memory
Windows 7 didn't bat an eyelid with respect to license although Office needed to run an automatic check
After a bit of fiddling I got the 4 cores recognised
However - due to not recording it before updating I have no idea which drive letter the CD Rom drive was allocated 
Is there a method of checking where Windows thinks the CD drive should be - is it in the registry somewhere

[#2]

Can you clarify the question?  If the CD Rom has been attached to the computer then it should have an allocated drive letter and you should see that in Computer. 

[#3]

The only time it might matter that I can think of is if you need the original Windows DVD for something like a driver (re)install.  In that case it will either (1) identify where it expects because it is a DVD, in which case the drive letter won't matter, or (b) identify it by (old) drive letter, in which case you will learn the old drive letter and can reassign the drive then.

[#4]

Control Panel ==> Administrative Tools ==> Computer Management ==> Disk Management is all!

[#5]

@sjptd
that is indeed the scenario
and of course with some games they get really upset if the DVD isn't in the drive where they expect it
I hope I have guessed right but only time will tell

[#6]

If you got it wrong then the instructions provided by NedLudd will let you change the drive letter.  You might have to do a shuffle but that's no problem. 

[#7]

An update
Windows suddenly decided it needed to revalidate the license but did it automatically via the on-line system

[#8]

Jim , if games need a CD in drive dont you ever use DAEMON Tools? its a CD emulator 

[#9]

never bothered and to be honest it was a long time ago when I last bought a game which needed a CD in the drive - everything seems to be geared to Steamn, Uplay etc. nowadays