So you have just unpacked and turned on your new computer.

First follow the instructions on the computer screen until you get to the Windows Home Page.

Check the time and date on the computer

Run Windows update until they are done

Run PC Decrapifier to get rid of all the preinstalled software / trials and pre loaded security software such as Norton or McAfee that you will never use and that just slows down your computer

Install Microsoft Security Essentials if you don't want to pay for a antivirus solution or Nod32 if you want a paid version that runs quietly in the background doing an effective job.

Open Windows Explorer and turn off the hiding of file extensions and make hidden files visible.

Go to folder options

 
Then open view

 
Remove the tick from " Hide extensions for known file types "

Click on the " Show hidden files, folders and drives "

Install an alternative browser , Firefox or Chrome

Then install the drivers for your peripherals , mouse , keyboard etc though with Windows 7 just plug them in and take the one's offered.

The printer drivers offered with Windows 7 are quiet good so again it is , plug and play.

You can then begin installing your software.