Need help deciding between two computers; I don't want to make the same mistake three times...?

I need help deciding on two computers

One is this Dell computer built from the website for $850 Total (shipping and Tax included). The reasoning for the low end hardware is because it's cheaper to upgrade afterwards than it is while building it.

PROCESSOR: Intel庐 Core鈩? Duo Processor E6550 (4MB L2 Cache, 2.33GHz, 1333 FSB)

OPERATING SYSTEM: Genuine Windows庐 XP Home Edition (will upgrade to XP Pro)

MONITOR: No Monitor

MEMORY: 2GB Dual Channel DDR2 SDRAM at 800MHz- 2DIMMs (Will upgrade to 4GB)

HARD DRIVE: 320GB Serial ATA Hard Drive (7200RPM) w/DataBurst Cache鈩? (Will upgrade)

OPTICAL DRIVE: 16x DVD+/-RW Drive (Will buy addition drive later)

VIDEO CARD: Integrated Intel Graphics Media Accelerator 3100 (Will upgrade to Nvidia GeForce 8600 GTS 512MB RAM)

SOUND Integrated 7.1 Channel Audio (Will upgrade to Sound Blaster)

FLOPPY %26 MEDIA READER: Dell 19 in 1 Media Card Reader

The other is an HP Pavilion for $1230 Total (with tax)

Processor: Intel Core 2 Quad Q6600

Need help deciding between two computers; I don't want to make the same mistake three times...?panda

I'm wondering why you don't build your own if

1. you already planned on spending that much and

2. you are already planning on upgrading so many things

If you built your own you might even save a little plus pre-built manufacturer's computers usually don't upgrade too well.