Unable to shrink 1.5Tb drive smaller than 651Gb

I just purchased a new HP Pavillion with a 1.5 Tb drive. I want to shrink the C: drive down to about 100Gb, and create other drive letters, with roughly 500Gb, 500Gb and 400Gb.

I went into Disk Management and began the process by attempting to shrink the C: drive, but the smallest it would let me shrink it was 651Gb. I got a message saying that unmovable system files prevented it from shrinking any more.

I tried defragging, but that didn't get me any more shrink.

Then I tried disabling the paging file and defragging again, but that didn't gain me any more shrink.

Calls to HP support didn't help. They said this was outside the scope of their warranty.

Any help?

BTW, the OS is Windows 7 Home Premium.

Check out the top answer to the question about this here:

partitioning - How to shrink Windows 7 boot partition with unmovable files - Super User

Your system specs say Dell?
If the HP is another new PC then I suggest you post a screenshot from the "Disk Management" view. Type disk management in the lower search box, use the Windows snipping tool and upload using the little paperclip on the psotings toolbar.

Be careful with HPs they typically use 3 primary partitions for other things and leave the user ONE primary Windows partition. You can only have 4 primary partitions on a disk. You can convert your HDD to a dynamic disk by trying to create more. This is not a good thing to do.