No more deleting your files if you are running out of space from a particular disk, in this article, you will find step by step tutorial on  How to Resize Partition Windows 7 For Free.
Before partition
After partition
You can see that i have taken 60 GB from my c drive and made a new drive [highlight]rtt stuff[/highlight] of 60 GB from it.
Let see how to do it:
1. Go to start menu >> computer >> right click it >> manage.
Be patient, it may take few minutes depending on the size of your disk.
4. Select the amount to be shrink this will be equal to the new drive that you want to create,
Like I want to make my new drive of 60 Gb (61440 MB) so I will shrink it to 61440 MB.
5. Click next and select NTFS partition and click finish. You will have to wait for some time.
Now you can see a new unallocated disk has been created.
- File system: NTFS (better for large volume)
- Allocation unit size: default.
- Volume name: give it any name you want here ii have used RTT stuff as my volume name.. you can change it later tough.
How to add a partition to existing drive
Now we know how to cut off the extra space from your hard disk and make a new drive but what if we want to add this free space to another existing hard drive partition.
So here I will delete the RTT stuff drive to get some extra space. Click yes to confirm the deletion.
Now once you have the unallocated space back, select the drive of which you want to increase the disk space >> right click >> extenD volume.
Again I will be adding this to my c drive.
Click next and wait for a while for the process to complete.
That is it, check you my computer now you will find the space added to your desire drive.
Tips :
You can use free  disk partition software like
Extend volume disable
Here you can see that unallocated space and c drive share a common border and it comes to its right side, this is the reason you will find the extend volume disabled. (in my case  D drive 162.5 GB). To fix this type of problem you can use third-party software.