You'll find the chipset drivers on the support site. 

Windows 7 (64bit)

http://www.dell.com/support/drivers/uk/en/ukdhs1/DriverDetails/Product/inspiron-15r-n5110?driverId=K2NV2&osCode=W764&fileId=2731100216&languageCode=en&categoryId=CS

This is the driver for the card reader here: http://ftp.dell.com/chipset/R292473.exe

Ensure that you review Windows Reinstallation Guide/A Clean install of Windows 7 (Step 4, 5, 9, 10 and 12) if you have manually installed the OS and are trying to install all the drivers:

http://philipyip.wordpress.com/dell-community-forums/