Yeah to the best of knowledge if you screw around with that with higher versions of Win 7 it will not like it and wont boot...But it can technically be removed if you dont have the bitlocker accessory available to you (MS frowns upon it and says to leave it)...BUT I never tried it as its only 100mb.
Here is MS's take on it and why you should
not mess with it (debbie's answer):
Can I delete the system reserved partition from 100MB
If you want to mess around with it:
Hack to Remove 100 MB System Reserved Partition When Installing Windows 7 My Digital Life