Intel® 915G Express chipset
Intel® Pentium® 4 processor with 800 MHz front side bus and Hyper-Threading
and 1MB L2 cache or Celeron D® processor with 533 MHz front side bus and 256K L2 cache
Intel® Graphics Media Accelerator 900
40, 80, 160 and 250GB 7200RPM Serial ATA (500GB may work)
Broadcom® Gigabit5 570XX Network Connection
Soundmax ADI 198x Integrated Audio Driver
You can install Windows 7 32-bit (x86), W7 will detect most of the above devices, but for the ones it won't, aslong as you have a network connection, window supdate may procide the rest, if not, use the Vista driver.
Don't rely on Dell for drivers... even their so-called up-to-date drivers can be months or even YEARS old. If you know what hardware you have, go to the source... Intel for chipset drivers and video drivers, Broadcom for ethernet driver, etc etc. Still, if you can't find the drivers anywhere else, XP drivers from Dell's site might work in a pinch.
windows 7 install with an active internet connection will load ALL drivers for you and just in case it doesn't then after the first or second (first) Win7 will find updated versions of of drivers and install them too.
I've personally done it and personally did it with gx280 mini-tower:
lga775 socket P4 (3.6ghz) HT
4GB ddr2 667mhz
nVidia 8600GT card
seagate barracuda 7200 rpm sata HDD
WEI scores on that unit (some people like WEI...)
4.4 or 4.6 cpu
all drivers loaded by win7 during install like i said.
of course you have to run win7 32-bit.
unit will not run 64-bit.