I am not sure if its windows 7 or ThinkPad. But I have some extra drives created in my system when I did the factory system recover.
I saw this when I checked my system with Hiren’s Boot CD’s Mini XP. The drives are:
B: RamDrive – 500 Mb
C: SYSTEM_DRV – 1.7 Gb
D: Windows7_OS – 100 Gb
When I boot into windows, its shows only C drive which is 100 Gb.
What is the issue here? Should I do something? Sorry if this is some common thing. I jumped from Windows XP to Windows 7, so I am unaware of the recent changes.

B is the ramdrive created by the boot cd to run, it is (as per the name) entirely in the ram, and will be removed when the system restarts.

C *may* be the recovery image location, I'm not entirely sure, this is my best guess

D is your normal C drive, and has your windows installation and everything.

you don't have to do anything, this is all normal behaviour for your system and the boot CD.

I hope you like windows 7, I like it a lot more than windows xp.