I upgraded to Microsoft’s latest, slick, OS this weekend and it sure was an adventure ride. However, at the end I was able to sort out things, thanks to several windows help boards. So, here are my two cents of advise for you to do before you take the plunge.
1) Back up everything on an external media: Pretty obvious? But so many of us continue to believe in the thrill, only to find Dilbert’s law applied. This is not yet another software installation. It is an OS upgrade. Please, please take a good comprehensive back up.
2) The most important tip. Remove/uninstall any fast access finger print/ camera recognition software that you may be using, before you start the upgrade process. Or visit the website of the device manufacturer to get a software update. I will come to my recommendation for doing this at the end of point 3.
3) Get a software update of the display driver that you may be using before you commence the upgrade.
Reason for advise # 2 & 3. When I upgraded my windows 7 to 10, all seemed fine. Until it booted up one final time during the process and all I could see was a screen frantically flashing. Unable to do anything, I shut the system down and used my phone for search for solutions. Visiting various forums, I shortlisted the key findings to these two issues. For me, it was #2 that worked. And of course, since Windows 10 (apparently) does not feature a safe mode boot, getting to the control panel to uninstall that software was a challenge. And coming to my rescue was the trusted pal control- alt- del. Pressing that repeatedly when the screen flashed, I was able to finally log on. Uninstalled the face recognition software, rebooted and woohoo, was good to go!!
4) Now this one is after you upgrade to Windows 10. Disable Windows Update Delivery Optimization (WUDO)?
Save your bandwidth. Read this great article, which is self explanatory. http://thehackernews.com/2015/08/windows-10-update.html