Windows 7 Do I Need an Upgrade?

[Jorge Coello]

Hello everyone, I've been thinking about upgrading my computer for a few months. I had already upgraded my graphics card before, and no problem there. I've been thinking of moving my ugly Dell Optiplex 755 parts into a Zalman Z9 Plus case. With this upgrade, I am also thinking about upgrading the CPU, I mean, why not? So I picked out an Intel Core i3-550 @ 3.2GHz. It's around 90-100 bucks. The current motherboard installed is the default Dell 0PU052. Do I need to upgrade in order to host this new CPU? If so, any recommendations? Oh, and as for the case previously mentioned...Would all my parts fit? Would I need to upgrade the power supply, or anything else? Thanks for the help.

{Full Computer Specs}
Operating System
Microsoft Windows 7 Ultimate 64-bit SP1
CPU
Intel Core 2 Duo E6550 @ 2.33GHz 40 °C
Conroe 65nm Technology
RAM
4.00 GB Dual-Channel DDR2 @ 332MHz (5-5-5-15)
Motherboard
Dell Inc. 0PU052 (CPU)
Graphics
DELL E178FP (1280x1024@60Hz)
NVIDIA GeForce GT 620
Hard Drives
233GB Western Digital WDC WD2500AVCS-572DY1 ATA Device (SATA)