How to Upgrade From Windows 7 32-Bit to Windows 7 64-Bitby Steven S. WarrenUpdated September 15, 2017
If you currently own a 32-bit version of Windows 7, you must purchase a licensed copy of Windows 7 64-bit to upgrade. Upgrading to a 64-bit operating system (OS) allows you to take advantage of more memory on your computer. On a 32-bit OS, you can only leverage 4 GB of memory. On a 64-bit system, you can have up to 128 GB of memory. Unfortunately, there is no easy upgrade path from a 32-bit version of Windows 7 to a 64-bit version of Windows 7; you must perform a clean installation of Windows 7 64-bit.
Back up all important data prior to performing a clean installation of Windows 7. You can back up your data to cloud/Internet services, an external hard drive, a USB drive and/or a set of DVDs. This process can be very time-consuming but you should take your time to properly back up all of your software to ensure you do not lose any of your data.
Obtain all computer drivers for a 64-bit Windows 7 system before performing a clean installation. Download the proper drivers to your backup media from the proper third-party website. For example, if you owned a Gateway computer, you would go to the Gateway website and enter your model number to download the proper Windows 7 64-bit drivers.
Turn on your computer with the Windows 7 installation media inside the DVD tray. Press any key to begin loading Windows 7 64-bit. Select "English" as your language and click "Install Now." Tick the box "I accept the license terms." Click "Next" and click "Custom" installation. Select your existing partition and select "Drive Options." Select "Delete" to delete the existing partition.
Click "Next" and a clean 64-bit installation of Windows 7 proceeds. Once your installation is complete, reinstall the software and drivers that you backed up earlier. Reloading your software and drivers is the most time-consuming part of this process and could take several hours depending on the size of your backups.