Im thinking about buying a used system withthe following specs. Can someone tell me if this will be good enough to edit HD files on pinnicle:
Specifications:
Processor Brand: Intel
Processor: Intel Core(TM)2 Quad
Processor Speed: 2.4GHz
System Bus: 1066MHz
Cache Memory: 8MB at die Level 2
System Memory (RAM): 3GB
System Memory (RAM) Expandable To: 4GB
Type of Memory (RAM): PC2-5300 DDR2 SDRAM
Hard Drive Type: Serial ATA (7200 rpm)
Hard Drive Size: 320GB
Graphics: ATI RADEON HD 2400 PRO
Video Memory: Up to 128MB
Personal Video Recorder (PVR): No
TV Tuner: No
MPEG: Yes
Audio: 7.1-channel support
Built-in Web Cam: No
Modem: 56 Kbps*
Network Card: Built-in 10/100/1000 Mbps Ethernet LAN (RJ-45 connector)
Wireless Networking: None
Recordable DVD Drive: Yes, DVDRW/CD-RW
Direct-Disc Labeling: No
Digital Media Reader or Slots: No
Diskette Drive: No
Total Expansion Bays: External: 2 (5.25") Internal: 2 (3.5")
Available Expansion Bays: External: 1 (5.25") Internal: 1 (3.5")
Total Expansion Slots: 3 PCI, 1 PCI-E x1, 1 PCI-E x8, 1 PCI-E x16
USB 2.0 Ports: 10 (2 front, 6 rear, 2 internal)
IEEE 1394 Ports: Yes
S-Video Outputs: 1
Additional Audio/Video Connectors: 1 S/PDIF, 1 eSATA
Serial Ports: None
Parallel Ports: None
Game Ports: None

For reasonable editing you need at least 2 but preferably more hard disks. One for OS/programs, one for media, one for projects/exports/render is about the minimum for any comfort. Also the included video card is weak to say the least, not enough memory for HD editing. If the price is right and you have included the price for one of two additional disks, realize that this case is full. No more expansion possibilities internally. Seriously look at the power supply, whether that can handle two additional disks and look closely at the cooling. When the case is full, you may be taxing the cooling.

To the best of my knowledge, there is no such thing as an HD 2400 PRO with only 128 megs of memory.

3 gigs if ram is skimpy. even 4 is bare minimum. AE prefers 2G of ram PER core, or 4 Cores X 2G = 8G. that would be my base minimum system spec. RAM is really cheap these days, so having 8G+ is not a big deal... I might say pass

You have to be running a 64bit OS to be able to use more than 3 gigs of memory. With a 32bit OS, more memory is simply not used.

I take it that this used system is not for editing and gaming (weak graphics card). Systems get outdated rapidly and don't expect to keep this one more than 2 or 3 years if you're a hard-core video editor. If the mobo has enough expansion slots, then you should be fine during that time. If you want to go the used route, look for a gaming computer which tends to have better components and (hopefully) a person who is always motivated to upgrade their systems (thus requiring the sale of a 'older' system).

An ATI HD2400 is quite adequate for editing, if you use an NLE, like Vegas, that doesn't use the GPU to accelerate anything. I assume the CPU is a Q6600, which is a reasonably powerful CPU for editing in HD (aside perhaps, from native AVCHD editing).

Well, I'd advise him to get a faster quad core processor. I had a machine with the Q6600 2.4GHz processor and that same ATI card. That combo will edit HDV but if he finds himself moving into AVCHD that combo won't quite cut it with software that does use the GPU. And that processor speed falls a tad short of what Pinnacle calls for in AVCHD editing.

I had to replace the ATI card with an Nvidia 8800GT 512MB card in order to edit avchd. I use Pinnacle Studio 12 Ultimate.

I just replaced that computer with an Intel Core i7 based machine. Works much better.