Second Hard Drive Problem "Please Help"

[Nokturnal]

I recently just bought some RAM and a second HD
1 x Western Digital Caviar Blue 500GB 7200 RPM SATA 6.0Gb/s 3.5" Internal Hard Drive -Bare Drive
To add some extra space to my computer, now when I hook up the drive, my computer either freezes up often or restarts randomly. I've tried it without the drive, and haven't got any problems, so im pretty sure its not the ram.
Really need help here im pretty lost ty.

Im Running Win7 and here is my build

1 x Antec Three Hundred Illusion Black Steel ATX Mid Tower Computer Case
1 x ASUS M4A79XTD EVO AM3 AMD 790X ATX AMD Motherboard
1 x HIS H577F1GDG Radeon HD 5770 (Juniper XT) 1GB 128-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFireX Support Video Card
1 x OCZ Fatal1ty OCZ550FTY 550W ATX12V v2.2 / EPS12V SLI Ready 80 PLUS Certified Modular Active PFC Power Supply
1 x AMD Phenom II X4 945 Deneb 3.0GHz Socket AM3 125W Quad-Core Processor HDX945FBGIBOX
1 x Mushkin Enhanced Blackline 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1333 (PC3 10666) Dual Channel Kit Desktop Memory Model 996652
1 x SAMSUNG Spinpoint F3 HD502HJ 500GB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
1 x Sony Optiarc 24X DVD/CD Rewritable Drive Black SATA Model AD-7240S-0B - OEM
1 x Microsoft Windows 7 Home Premium 64-bit 1-Pack for System Builders - OEM m -

 

[Nokturnal]

I'm starting to notice, it either freezes up completely , restarts, or windows explorer restarts mostly when im doing a task, such as playing a game, moving files that are large, loading up cubase(audio programs).

 

[Nokturnal]

I've been thinking and is it possible it could be my powersupply, I just didn't think a small item could cause it, but I am running everything on my computer 3 fans+Studio Speakers+Studio Mic+Studio Keyboard+External M-Audio Sound Card, I really need some feed back to see if it is possible that its my powersupply before i buy a new one, if so, anyone got some suggestions on a new one, Thanks.