How Can I Install Windows Without the Disk

You can legally download Windows 7 and make your own install disc. Most of computers ship without Windows 7 installation discs. They come with recovery discs and partitions that claim to restore your PC to its factory  state.

You'll learn how to make your own Windows  installation disc or USB flash drive. You can use the valid product key you already have to perform a fresh installation. The following method is effective and legal, and doesn’t require a lot of technical expertise.

First you have to save your files and drivers to external media before you start. Reinstalling Windows wipes out all personal data and causes a loss of functionality in devices for which Windows lacks an adequate built-in driver.

Reinstalling Windows 7, Step by Step

1. Find your Windows 7 product key: Typically this 25-character alphanumeric string is printed on a sticker affixed to your PC or on documentation included with your PC. Alternatively, you can use a key finder program such as Magical Jelly Bean Keyfinder to pull your product key from the Registry. You need your product key to reinstall Windows. Magical Jelly Bean Keyfinder helps you round up your serial numbers.

2. Download the ISO file for the version of Windows  you own

Home Premium SP1 (English, 64-bit)
Professional SP1 (English, 64-bit)
Ultimate SP1 (English, 64-bit)
Home Premium SP1 (English, 32-bit)
Professional SP1 (English, 32-bit)
Ultimate SP1 (English, 32-bit)

The above links point to Digital River, a licensed distributor of Microsoft software. These downloads are each over 3GB, and your product key will work only with your edition of Windows, so make sure to select the right one.

3. Download the Windows 7 USB/DVD download tool. This utility lets you copy your Windows 7 ISO file to a DVD or USB flash drive. Whether you choose DVD or USB makes no difference; just confirm that your PC can boot to the media type you select.

4. Boot your computer using the Windows 7 DVD or USB flash drive. Follow the prompts to prepare the destination hard drive and install Windows.