I agree with Patcooke up to a certain point:
I agree that you should burn your recovery disk before you go about making any changes(Great suggestion Mate 

)
How ever i feel that you dont need any third party software to create any further partition as in windows 7 you have all the options in built:
Heres how:
 SHRINK EXISTING PARTITION
  Using Disk Management 
1. Open the 
Control Panel (All Items view), and click on the 
Administrative Tools icon. then close the Control Panel window.
 
 
2. Click on 
Computer Management in Administrative Tools, then close the Administrative Tools window.
 
 
3. In the left pane under 
Storage, click on 
Disk Management. 
4. In the middle pane, right click on the partition that you want to shrink and click on 
Shrink Volume. 
 
 
5. Type in how many 
MB  (1 GB = 1024 MB) of the available shrink space shown that you want to  shrink the partition or volume by to be used for the new unallocated  space, then click on the 
Shrink button. (See screenshot below)
The 
size of the available shrink space can be restricted by the amount of space currently allocated to on the hard drive for the 
virtual memory page file, 
System Protection maximum storage space size, and 
hibernation files. The location of the files on the hard drive plays a big part here because these files are marked as 
unmovable,  and Disk Management is unable to relocate them. As such, if these  unmovable files are located in the middle of the total amount of free  space on the disk, then only the amount of free space on the other side  (to the right) of these files will actually be available for the new  partition. This will result in you showing that you have x amount of  free space, but not being able to use it for your partition. The only  way around this is to use a 3rd party hard drive partition management  program, or setup the partition when installing Vista.
6. The selected partition (step 4) has now  been shrunk to create a new empty unallocated space. You can use this  new unallocated space to 
create a new partition with. 
7. Close the Computer Management window. 
 CREATE NEW PARTITION
  Using Disk Management 
1. You will first need to 
shrink a partition or volume  from the free space on a disk to create unallocated space on that disk  to use to create the new partition or volume with on the same disk.
 
 
2. Open the 
Control Panel (All Items view), and click on the 
Administrative Tools icon. then close the Control Panel window.
 
 
3. Click on 
Computer Management in Administrative Tools, then close the Administrative Tools window.
 
 
4. In the left pane under 
Storage, click on 
Disk Management. 
5. In the middle pane, right click on the empty 
unallocated partition or volume and click on 
New Simple Volume. 
 
 
6. Click on the 
Next button. 
7. Type in how many 
MB (1 GB = 1024 MB) you want to use from the unallocated partition to create the new partition with, then click on the 
Next button. 
 
NOTE: If  you want to use all of the unallocated partition to create the new  partition with, then type all of the maximum disk space shown for the  unallocated partition. If you do not use all of the maximum disk space,  then you can use the left over space from the unallocted partition to  create another new partition with.
8. Select an available drive letter that you want to be assigned to the new partition in Computer, then click on the 
Next button. 
9. Type in a 
volume label name that you want for the new partition, check the 
Perform a quick format box, and click on the 
Next button. 
10. Click on the 
Finish button.
11.  The new primary partition or volume has now been created with the  assigned unallocted partition space (step 7). 
12. Close the Computer Management window.