Like King Canute trying to hold back the incoming tide, you may still be holding out on Windows 8. Windows 7 is still a great operating system and it will continue to provide good service for a long time to come, but Windows 8 isn't going to go away. With 8.1, Microsoft continues with the themes introduced with 8 like the Start screen and apps.
You don't have to completely replace Windows 7 though and you can run both Windows 7 and 8.1 side by side on the same PC on the same disk drive. Providing you have around 20GB of disk space free on the hard disk drive, you can install Windows 8. You just need to do two things.
The first of the two things you need to do when installing Windows 8.1 on a PC running Windows 7 is to shrink the Windows 7 partition. This creates empty space into which you can then install Windows 8.
In Windows 7 click the Start button and then type
disk management. Click the one and only item displayed at the top of the Start menu and the Disk Management utility appears on the screen.
Disk Management displays the drives, disks and partitions attached to the PC. DRive C: is where Windows 7 is installed and you should ignore the tiny System Reserved partition that's just 100MB.
Right click drive C: and select Shrink volume. It's really up to you how much you shrink it by. Note that the numbers displayed are megabytes and the minimum amount of space for installing Windows 8.1 is 20,000MB (20GB). With drives of 500GB common these days, you could easily free 100GB of space for a Windows 8.1 partition.
Shrink the volume and the first step is done.
Pop a Windows 8.1 DVD into the CD/DVD-Rom drive and start or restart the computer. It will boot from the disc and run the Windows 8.1 installation procedure. Very early on in the installation, before anything is actually written to the disk drive, it asks you which type of installation you want, upgrade or custom. Select Custom.
The second thing you need to do to get Windows 8.1 installed alongside Windows 7 is to choose the free space you created when shrinking the Windows 7 partition. Select the unallocated space, not the partition with Windows 7 on!
Of course, there are many steps involved in installing Windows 8 and one or more reboots, but shrinking the Windows 7 partition and selecting the empty space for Windows 8.1 are the only two things you need to remember.