How To Partition Hard Drive Without Losing Data - Computer Tricks.

Before starting note that:
We can partition any drive, even a system drive
We can do it only in Windows XP, Windows 7 and Vista specifically
Follow these simple steps

Go to Start > Right click on My Computer and choose Manage.
Disk Management Window will Pop-up, it may take time to load it since
it fetches for all the hardware and system information in your PC.
After it's fully loaded, go to Storage> Disk management at the left
sidebar. This is where we'll have all the information about storage
devices that are in our PC currently connected and active.
At the right column all the storage media will be listed with their
basic information like File system type, and status.
Now choose the Volume that you want to partition. Right Click on it
and select Shrink Volume option from menu.
As soon as you click on the Shrink Volume option, system will search
for available space in your selected Disk Volume.
This will not take much longer than few seconds. After querying,
Shrink window will pop-up. This is where you'll have to specify the
Volume for next partition.
Look at the total size of available shrink space. Below it, you'll
have to Enter the space to shrink.you must make sure that the size is
not below the total size of space taken by files in that drive.
You can check the used space by right clicking on the drive you are
going to partition and choose Properties.
Click on Shrink button after specifying the size to shrink.
The shrink size is for the value for the partition where your old
files will be contained and remaining size will allocated for your
next partition.
But you'll still not able to access this new drive. You'll have to
format it and specify the drive letter to access them. To do so,
continue reading...... :))
Format the new drive

Right click on unallocated drive and choose New Simple Volume option.
New Simple Volume Wizard Window will popup.
Click on Next button to continue.
In next window, you'll have to specify the size for your new volume.
Set full size if you are satisfied with two partitions; else divide it
again for new partition.
Next choose any drive letter from the available list and click on Next button.
In next window, leave everything as default.
Click on Finish window to complete the wizard.