Will I be able to install my old hard drive into my system?

Okay, I'm just a bit scared of installing my old hard drive into my new system as I could go over the limit of Watts

I have a 450W Quiet 80 PLUS dual rail.

Here's my setup:

CoolerMaster Elite 310
AMD Phenom II x4 945
ASUS M4A78LT- LE: mATX
4GB DDR3 1333MHz (2 X 2GB)
1GB RADEON HD 5770 PCI EXPRESS
1TB SATA HARD DRIVE (3-Gbs/7,200rpm)
24x Dual Layer DVD writer +R/+RW/RAM
Internal 52 in 1 card reader
Standard AMD CPU cooler
Onboard 7.1 sound
Onboard network facilities
2 fans

I only want to install this new hard drive to either transfer all of my data to my new PC and might use it.

Thanks in advance  .