How to download and install Windows 10 even if GWX.exe is missing:
Step#1: Open Microsoft’s new Windows 10 download page.
Step#2: Now choose 64-bit version, if your computer doesn’t have a 64-bit processor then select 32-bit version.
Step#3: Click on save file and choose run.
Step#4: You’ll be presented with two options; Upgrade now, or create installation media. Choose upgrade now.
Step#5: Now Windows 10 will start downloading, wait until downloading is complete.
Step#6: Once download is completed agree to licence terms when prompted. Now installer will check your PC if its compatible for Windows 10 and have enough space then it will start downloading the updates.
Step#7: You will not need the Windows activation key if your pervious version of Windows is eligible.
Step#8: After the downloading process is complete choose install Windows 10 when promoted. Now sit back and wait for installation to be completed.
Step#9: Once installation process is done, Windows 10 desktop will show up. All Done.