please install the driver in following order(especially the begining two).

Intel mobile Chipset driver for Dell D630 laptop
ftp://ftp.us.dell.com/chipset/R153997.exe

Intel Matrix Storage Manager driver for dell D630 Notebooks
ftp://ftp.us.dell.com/SATA/R154200.exe

driver for D630 audio: STAC 92XX C-Major HD Audio
ftp://ftp.us.dell.com/audio/R171789.exe

Conexant modem Driver for D330,HDA,MDC,v.92,modem
ftp://ftp.us.dell.com/comm/R167368.exe

Broadcom Driver for D630: 57XX Gigabit Integrated Controller
ftp://ftp.us.dell.com/network/R151327.exe

Intel Video Driver for GM965 Express Chipset Family
ftp://ftp.us.dell.com/video/R181739.exe

nVidia Video Driver for Quadro NVS 135M
ftp://ftp.us.dell.com/video/R180876.exe

drivers for Dell D630 Wireless 360 Module with Bluetooth 2.1 + EDR
ftp://ftp.us.dell.com/network/R181542.exe

Dell - Driver for:
Wireless 1490 Dual-Band WLAN MiniCard
Wireless 1505 Draft 802.11n WLAN Mini-Card
Wireless 1390 WLAN MiniCard
Wireless 1395 WLAN MiniCard
ftp://ftp.us.dell.com/network/Dell_multi-device_A17_R174291.exe

Wireless Driver for Intel(R) PRO/Wireless 3945ABG Network Connection
ftp://ftp.us.dell.com/network/Intel_multi-device_A13_R171131.exe