Gaming system for $1000 or less

You can't download the Windows 7 RC from Microsoft any more. That ended on the 20th. Here's a build that comes in right at the upper end of your budget, but is very nice:

AMD Phenom II X3 720 2.8GHz 3 x 512KB L2 Cache 6MB L3 Cache Socket AM3 95W Triple-Core Black Processor - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103649

Antec TruePower New TP-550 550W Continuous Power ATX12V V2.3 / EPS12V V2.91 80 PLUS BRONZE Certified Active PFC Power Supply - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371020

http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.233382 $178.99 (case + PSU combo)

GIGABYTE GA-MA770T-UD3P AM3 AMD 770 ATX AMD Motherboard - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128392&Tpk=gigabyte%20sb710%20770

Microsoft Windows Vista Home Premium SP1 64-bit for System Builders w/ Tech Guarantee - OEM (Includes free Windows 7 updrade coupon)
http://www.newegg.com/Product/Product.aspx?Item=N82E16832116677

http://www.newegg.com/Product/ComboDealDetails.aspx?ItemList=Combo.234361 $169.98 (motherboard + OS combo)

mushkin XP 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Dual Channel Kit Desktop Memory Model 996657 - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16820146871 $99.99

SAPPHIRE Vapor-X Radeon HD 4870 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102825 $149.99

Western Digital Caviar Blue WD3200AAKS 320GB 7200 RPM 16MB Cache SATA 3.0Gb/s 3.5" Internal Hard Drive - OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136074&Tpk=wd3200aaks $49.99

COOLER MASTER HAF 922 RC-922M-KKN1-GP Black Steel + Plastic and Mesh Bezel ATX Mid Tower Computer Case - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119197 $99.99

SAMSUNG Black 22X DVD+R 8X DVD+RW 22X DVD-R 16X DVD-ROM 48X CD-ROM 2MB Cache SATA DVD Burner LightScribe Support - OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E16827151188 $30.99

ASUS VK246H Black 24" 2ms(GTG) HDMI Widescreen LCD Monitor 300 cd/m2 DC 1000:1 (ASCR 20000:1 ) Built-in Speakers w/ 1.3m Pixel Webcam - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16824236048 $219.99

Total - $999.91

i am doing a similar build, check this link to mine and see what i am looking at and what some people said. the overall build is fantastic for only 1000 or slightly under(after some posters suggestions dropped my price)

http://www.tomshardware.com/forum/270298-31-first-time-builder#t1980229