Don't know which drivers to install and can't install those that Dell recommends

I have a Dell XPS 15 (L502X, Early 2011) with Windows 7 64 bit operating system.

I've had to reinstall Windows 7 because I was having video freeze with a baamp noise and nothing else that I tried was working. Since my warranty is expired, the technicians at Dell provided me with very limited information. After I reinstalled Windows 7 from the DVD, I was confused about how to use the drivers and utilities DVD. A technician at Dell suggested that I download and install only the network drivers for my computer from the Dell website. He said Microsoft updates would install the other drivers that I needed. That didn't turn out to be the case. Although my computer is working much better (I'm not getting the video freeze or the baamp noise), it's not fully functioning.

Here are a few problems that I'm aware of:

1) As I type this reply, my curser is moving to different parts of the page, so maybe I need an update to my keyboard driver?

2) I ran a systems analysis for my express service code (a code that identifies my computer and it's systems/components)  from the drivers and downloads page at the dell.com/support site. I followed the instructions for the 7 driver updates that were recommended. However, even though they all appeared to be installed successfully, the analysis still shows ( I ran it several times after downloading the driver updates) that I need to install 5 of the seven drivers: Dell XPS L502X System BIOS, Intel HD 3000/2000 Graphics Driver, Intel HM67 Chipset Driver, Dell Touchpad Driver, and the Intel Management Engine Interface Driver.  I tried installing the first two drivers for a second time, but was unsuccessful.

I called the Dell out of warranty support desk again, and another technician suggested I try installing the drivers from the DVD, which is where I began to be confused. I don't know which drivers to select and install.

3) The device manager on my computer shows yellow exclamation points in the "Other Devices" section under the headings: Dell Wireless 5620 (EV-DO-HSPA) Mobile Broadband Mini-Card; SM Bus Controller; and Unknown Device.

4) The control strip features: #3 battery status light; #5 instant launch control; and #6 audio control-panel control, are not functioning.

Thanks for your input,