Help to select DeskTop Video Editing System

Dear All,
I'm a DeskTop Video Editor. I'm using Computer System along with Matrox RT2500 capture card with Matrox G450 Graphics Card. Now I would like to buy another DeskTop Video Editing System. In This case can I select the following one. But can I work with it without capture card?

HARDWARE:
Processor : Intel Core 2 Quad 2.40Ghz
Mainboard : Intel IX 38 Quad GT Abit
RAM : 2GB DDR2 1066Bus
HDD : 250GB + 250GB SATA-2 SEGATE
Optical Drive : DVD RW
Graphics Card : ATI 3870 SAPPHIRS 512MB
Sound Card : On Board
Power : 450W

Camera : 3CCD DV

SOFTWARE:
Windows XP
Adobe Premiere
Adobe After Efect
Adobe Photoshop
Adobe Flash

Please help me by reply.

Thanks in advance.
Moin