How to install Windows 7 from USB?

Microsoft has made it easier to install Windows 7 on newer computers that do not have an optical drive installed on them. They also have a tool specifically created for this purpose, so you don't have to find any third part programs. Just download the Windows 7 USB/DVD download tool from the Microsoft's website.

Install the software using following steps:

Step 1: Open the downloaded file and follow the steps in the setup dialogs. You'll have the option to specify where to install the Windows 7 USB/DVD Download Tool. You are going to need an administrator account on the computer where you are trying to install Windows 7 USB/DVD Download tool. The tool also needs the .net framework v 2.0 or higher.

If you are using Windows XP on your computer, then you need to download and install the following first, if not already installed.

1. Microsoft .NET Framework 2.0

2. Microsoft Image Mastering API v2

After the software is successfully installed, you will require an ISO image of your Windows 7 installation disc. If you already have that on PC, you're ready to go. In case you don't, download Imgburn to create a ISO image from the original Windows 7 DVD using a computer that has an optical drive. When you have the ISO, just follow the steps to create a USB based installer for Windows 7. Keep in mind that you need a USB drive with at least 4GB of free space.

Step 1: Click the Windows Start button, and click Window 7 USB/DVD Download Tool in the Programs list to open the Windows 7 USB/DVD Download Tool.

Step 2: In the box, type the name and path of your Windows 7 ISO file, or click Browse and select the file from the Open dialog box. Click Next.

Step 3: As you need to copy the system files to your USB drive, just select your USB device in the drop-down list and click begin copying.

After all the above steps are complete, you need to eject the USB drive from your computer and it is ready to be used on your friend's PC. Just select 'boot from USB' on his PC and start installing Windows 7.