Windows 7: Increase the size of C:

Hello everyone..I have a problem with increasing the size of the C drive..I have 160GB hard Disk..There was a problem that size of F drive got increased..But C got shrinked (how I don't know).Now I have freed space of F by shrinking and so I have 9.40 GB free space.But I can't use it for expanding C drive..By right clicking the expand option is showing unavailable..what I can do this in this situation?Is reinstalling Windows can fix the problem..here is the snap of my disc management.please help me out?
My operating system is Windows & 64 bit.

I wonder which Partition Manager you are using. But you can use Acronis Disk Director Boot CD to organise your partitions any which way that you would like, without affecting your data

Move the stuff from D to F and delete D. Then you can extend C. Might want to add the freespace to F first.

Boot into free Partition Wizard
bootable CD, rightclick on F, to select Resize, , drag to the right to take up the free space, click OK. Do the same successively to E and then D. Before clicking OK on D grab it's left grey border and slide it to the right to make more space for C, OK, Apply all steps.

You can now rightclick C to Resize, drag it's left grey border to the right, OK, Apply.

If this is not enough space for C, resize one of the other partitions smaller before sliding it over to the right.