Add free space to system partition of Win20003

I’ve a Win20003 Server Enterprise Ed. running MS Share Point Portal server. I’ve configured 3 partitions on it. Using C for OS, D for installations & E for data.

Now C drive is dangerously low in free space. Due to excessive use & document uploads on MS SPS, server, free space on C partition is less than 100 MB. MS SPS is actually instaleld on C:

Is there any tool / utility (preferably freeware or shareware) using which I can add free space from E: partition to this C: (system partition) without loosing data.

Thanks in advance.