It will took 24-48 hours to activate if you make a clean installation. So, upgrading from your previous version is recommended. There are lots of complaints on various forum saying they could not activate windows after clean installation. Microsoft also mentioned that you need to upgrade first before make a clean installation. However recently I found that after the installation, you need to log in to your Microsoft account (live account) and it will activated within 1 or 2 days.
2. Windows Version
Check your windows version so that you can upgrade for free, for example I am using Windows 8.1 Single Language so I can only install Windows 10 Home. If you install Windows 10 Pro Over Windows 8 (basic edition) you will need to purchase the activation key.
3. Create a bootable USB
You will have no problems if you are using DVD to install windows 10. If you are using USB, most current Notebook uses UEFI, it means using Windows USB/DVD released by Microsoft will not work. What what I did was download and install rufus, run the program and create a bootable USB. It has a feature where you can select to format it as GPT for UEFI because MBR only works for notebook tat using BIOS (not UEFI). You also need to select fat32 and not NTFS for the file system.
Upon power on your laptop, press F12 (other model might need to press other keys) to enter the boot selection, select your USB device to start install windows 10. . Remove your USB upon reboot so that it will not boot from the USB and restart the whole installation process again. If you familiar with BIOS/UEFI you can change the setting in the BOOT menu and set your USB as 2nd boot device and your HDD as the first boot device.
5. Product Key/CD Key/Activation
During installation, it will ask for Product Key twice. First time you just need to select Skip and the second select do this later. After the installation finish, just connect to the internet and it will automatically activated within 2 days . (If not you may need to contact Microsoft to sort it out, and of course someone did contact Microsoft using online chat and success, but he also mentioned how long he have to wait to resolve that matter.)
Windows 8 or Windows 7 driver should work in Windows 10, but the first thing you need to do is to run automatic updates because it will install the latest drivers for you notebook. I noticed on my Acer there are 3 drivers missing which is (you can check this on device manager):
Video driver : Basic Display Adapater
I use Intel HD driver, I got 4 options to install driver which are download from Acer website, Download from Intel website, run automatic update or directly right click and select update driver from device manager. I use the last option because it does not matter what version it will install, It's low end graphic and the driver won't show any significant improvement. (right?)
TXE Driver : I forgot the name before I installed the driver (lol)
However this driver will not updated automatically, I need to download TXE driver from Acer to install this driver.
SMS message access
This device is some sort of bluetooth component, I just need to install bluetooth driver from acer website. Since I didn't use Bluetooth, I just ignore and leave it there.
So there you go, If you have problems, question or suggestion, leave your comments on the comments section below.