The Dell website only reflects Vista drivers for that system.
Info on PCI Device PCI\VEN_8086&DEV_293E&SUBSYS_020D1028&REV_02\3&2411E6FE&0&D8 39:
Name: Microsoft UAA Bus Driver for High Definition Audio
Device ID: PCI\VEN_8086&DEV_293E&SUBSYS_020D1028&REV_02\3&2411E6FE&0&D8
Driver: C:\WINDOWS\system32\DRIVERS\hdaudbus.sys, 5.10.0001.5013 (English), 4/13/2008 09:36:05, 144384 bytes
The driver download applicable is listed under XP, SP2 at
http://support.microsoft.com/kb/888111.
Louis