Dell Optiplex 170 motherboard 
AFAIK, it's not a branded make/model such as Asus, Gigabyte, MSI - or whatever.
It's just a generic Dell part.
If you're asking because you need a replacement, I don't know if you'll be able to replace it with any MicroATX board?
I suspect you'd need to get it from Dell's own spare parts section?
From experience, I've found that: “Beauty is in the eye of the beer-holder”!!
XPS M1730:
Smoke Grey Magnesium Alloy Chassis - with White LED Backlights
17" UltraSharp WUXGA Widescreen TFT (1920 x 1200) with TrueLife
Intel Core 2 Duo Processor T9300 @ 2.50GHz (800 MHz FSB, 4MB L2 cache)
4GB (2x 2GB) Patriot Signature PC2-5400 @ 667MHz
DUAL 512MB Nvidia 8800M GTX cards in SLi + 128MB Ageia PhysX
640GB SATA II (2x 320GB WD Scorpio Black 7200rpm)
8x Super-Multi DVD±RW
Creative X-Fi Notebook (ExpressCard) + Creative GigaWorks T40 Series II
Integrated 2MP Webcam
Dell Wireless 355 Bluetooth 2.0 Module
Intel Next-Gen Wireless-N Mini-Card
TV Tuner and Dell Travel Remote Control
4-in-1 Flash Card Reader (SSD/MMC/MS Pro/xD)
230W AC Adapter / 9-cell Lithium-Ion Battery
Windows 7 Home Premium (64bit)