In order for us to help you, please fill out the following template. I'd recommend that you build your own rather than buy a prebuilt. Prebuilts are overpriced...they throw in one or two decent parts and then shroud it in poo parts. Building isn't that difficult. I can link you to a few great tutorials on youtube. It's simple stuff. It'll save you a ton of money and hassle.
Approximate Purchase Date: e.g.: this week (the closer the better)
Budget Range: (e.g.: 300-400) Before / After Rebates; Before / After Shipping
System Usage from Most to Least Important: (e.g.: Folding@Home, gaming, surfing the internet, watching movies)
Are you buying a monitor: Yes / No
Parts to Upgrade: (e.g.: CPU, mobo, RAM) **Include Power Supply Make & Model If Re-using**
Do you need to buy OS: Yes / No
Please note that if you're using an OEM license of Windows, you will need a new one when buying a new motherboard.
Preferred Website(s) for Parts: (e.g.: newegg.com, ncix.com -- to show us selection & pricing)
Location: City, State/Region, Country - we need to know where these parts are being assembled and whether there are good store-only deals available
Parts Preferences: by brand or type (e.g.: I would like to upgrade to Intel CPU)
Overclocking: Yes / No / Maybe
SLI or Crossfire: Yes / No / Maybe
Your Monitor Resolution: (e.g.: 1024x768, 1280x1024, 1440x900, 1600x1200, 1680x1050, 1920x1080, 1920x1200 or if you're upgrading please state what you'd want to get)
Additional Comments: (e.g.: Need to have a window and lots of bling, I would like a quiet PC. Please also list specific software or games you're using)
And Most Importantly, Why Are You Upgrading: (e.g. I'm having trouble running game X or my PSU broke)
Include a list of any parts you have already selected with descriptively labeled links for parts. Please do not post only links.