I prefer Windows 8.1 over Windows 8 and even with its flaws I enjoy it more than Windows 7.
Always backup before upgrade or any major system modification
For home use you can use EaseUs or Macrium, links below to create a system image.
To ensure you grab settings, mail, keys, favourites I recommend Fabs Autobackup, for a reasonable cost it does an amazing job.
From Windows XP
If you are looking to upgrade from Windows XP you’ll have to make a complete backup and do a clean install or setup a dual boot configuration by first doing a backup with EaseUs ToDo Backup Free or Macrium Reflect Free (ensure that you grab the appropriate bit version for your current OS) and then you can shrink your current partition and create a new one with EaseUs Partition Master Free.
A dual-boot configuration has the following benefits
- Allows you to do a clean install and transfer your files as and when needed.
- Gives you a backup plan, Windows 8.1 not working for something, boot to XP.
From Windows 7
If you’de like to transfer your settings as well as software, it looks like you’ll have to install Windows 8 [NG4HW-VH26C-733KW-K6F98-J8CK4] and then upgrade from there to Windows 8.1 – a lengthy process
Only have a Windows 8 Key but want to install Windows 8.1
If you have a Windows 8.1 ISO you can use a KMS Key to install and then change your product key afterwards to your Windows 8 key. For some reason 8.1 will not take the key during installation.
Windows 8.1 Pro KMS Key
or go here for others