We can't help you locate any drivers without knowing the model number of your Dell.

Assuming from your earlier posts on the forum you have an Inspiron 531s and also assuming the 64 bit version of Windows 7:

Windows 7 64 bit 

BIOS

1.0.13 http://ftp.dell.com/bios/I531_1013.EXE (latest BIOS)

Chipset and Ethernet

MCP 61 (nVidea nForce 430): http://www.nvidia.com/object/nforce_vista_win7_64bit_15.49.html 

Video

ATI Autodetect http://support.amd.com/us/gpudownload/windows/Pages/auto_detect.aspx

or

nVidea Autodetect http://www.nvidia.co.uk/Download/Scan.aspx

Modem

Conexant D850 Driver http://ftp.dell.com/comm/Conexant_D850-56K-V-9X-PCI-D_A00_R223419.exe *

Conexant D850 Utility http://ftp.dell.com/comm/R139937.exe *

Conexant D850 Application http://ftp.dell.com/comm/CONEXANT_MULTI-DEVICE_A09_R204990.exe *

Conexant D850 Diagnostics Utility http://ftp.dell.com/comm/Conexant_multi-device_A05_R177997.exe *

Audio

Realtek ALC888 HD Audio http://ftp.dell.com/FOLDER91041M/4/R243215.exe *

Network

Dell Wireless 1505 http://ftp.dell.com/FOLDER90848M/1/R228562.exe **

ASUS WL-138g PCI WLAN Card http://www.asus.com/Networks/Wireless_Adapters/WL138g_V2/#download

Card Reader

Dell Media Card Reader with Integrated Bluetooth Module (CAB-200), Media Card
Reader 19-1 with Integrated Bluetooth http://ftp.dell.com/rmsd/Dell_multi-device_A00_R152639.exe ***

* taken from Inspiron 570

** taken from Inspiron 545

*** Install in compatability mode for Windows Vista

This is an unofficial driver set and is unsupported by Dell please let me know if these drivers install or not.