Gx 260 Ethernet Controller - Dell Optiplex GX280 (99301) Motherboard

No,install audio device ADI 198x integrated audio driver.
Version:- A08
OEM Version:- 5.12.01.3538
Optiplex gx 260.

The built-in VGA on this computer is the Intel® 82865G Graphics and Memory Controller Hub (GMCH). The download page is here.

http://downloadcenter.intel.com/SearchResult.aspx?lang=eng&ProductFamily=Graphics&ProductLine=Desktop+graphics+controllers&ProductProduct=Intel%c2%ae+82865G+Graphics+and+Memory+Controller+Hub+(GMCH)&ProdId=1044&LineId=1100&FamilyId=39

This is a discontinued product and that is why it is difficult to find.

the driver for your model can be downloaded here . http://support.dell.com/support/downloads/driverslist.aspx?c=us&l=en&s=gen&ServiceTag=&SystemID=PLX_PNT_P4_GX260&os=WW1&osl=en&catid=&impid= there are several different kinds so your going to have to start the install to see which driver you need (windows should detect at least the adaptors brand)

Here they are:
http://support.dell.com/support/downloads/driverslist.aspx?c=us&l=en&s=gen&os=WW1&osl=en&catid=&impid=&SystemID=PLX_PNT_P4_GX260

Good Luck!!!!

Does it have a graphics card fitted? WHat sort?

i don't see any reason that you can't as long as you use the 260 drivers.

This driver should do the trick

http://support.us.dell.com/support/downloads/download.aspx?c=us&l=en&s=gen&releaseid=R145551&formatcnt=1&libid=0&fileid=194065

go to the Dell support site and enter in your Service Tag # -- this should give you access to all the drivers that originally came with computer,

if you don't have the cd with the drivers and utilities, then you can download the drivers online with another computer. (you will need a thumb drive or cd to save it on) you will also need to make sure you know what brand of ethernet card your computer came with. once you get that ethernet card working, you can get online and download the remaining drivers, possibly through windows update. be sure to select custom update, not express, so it will search for the hardware drivers for you.

Here you go.

http://support.dell.com/support/downloads/driverslist.aspx?c=us&l=en&s=gen&ServiceTag=&SystemID=PLX_PNT_P4_GX260&os=WW1&osl=en&catid=&impid=