Hi everyone, been a while since I last posted here, today's tutorial is on how you can have a full feel of Windows 10 technical preview without losing your present Windows 8/8,1 O.S.

NB: If you think BIOS is a new form of plant fuel, you probably should not continue with this tutorial; We don't want you to ruin your system.


I don't want you to ruin your present O.S so, it is advisable to upgrade your Windows 8.1 or 8 to Windows 10 TP because:

  • Windows 10 is still in it's TP stage, you can't depend on it as your daily O.S has drastic changes may come into place anytime.
  • This is not a release candidate, unknown bugs may occur more frequently than expected (my keyboard status lights are not coming on), so install as an optional O.S


The following are the steps to installing windows 10 TP alongside windows 8/8.1

STEP 1: Create a Partition for Windows 10.

Open Disk Management by following either of the options below;
  • Right click My Computer / This PC and click mange, to bring up Computer Management -> Click Disk Management.
  • Goto Run (Windows + R) and type diskmgmt.msc and click Ok.
  • Goto Control Panel -> System and Security -> Administrative Tools -> Computer Management

Right Click on the largest partition and click shrink volume. Enter the amount of storage space you want allotted to the new partition as it's size, (NTFS, 50 GB and above will be convenient enough for Windows 10 TP ).

You can get more shrink space if you defragment the drive before attempting to shrink so you can have a larger contiguous free space for shrinking.

STEP 2: Get / Download Windows 10 TP ISO

You can download Windows 10 TP for free by enrolling for the Windows Insider Program, Visit  https://insider.windows.com and login/sign up with your Windows Live account. Follow the onscreen instruction to get a download link to the latest revision of Windows 10 TP and a product key.

STEP 3: Create Bootable Windows 10 TP

If you think an ISO file is a document for International Standard Organisation, please stop reading here. :D

Follow the guidelines in this article:
How to Manually Create a Bootable USB disk for Windows 7 / 8 / 10 (UEFI / LEGACY)


1. Hold shift  and navigate to Restart (power icon ->restart ), continue holding the shift till the advance system menu comes up;

2. Click USB and click on your USB disk from the listed USB removable disks.

Your system will reboot into the Windows 10 installer follow the onscreen instruction and make sure you select the partition we built in step 1.

NB: If you are in a UEFI environment and it is not booting to Windows 10 Installer; disable secure boot from your BIOS.

NB: if you are installing as legacy and you're in a UEFI environment, you must enable legacy mode.

Here is a tutorial on how to create a bootbale usb removable disk or flash for Windows 7, 8 or 10.

If you think an ISO file is a document for International Organization for Standardization, please stop reading here. :D

if your flash is already prepped up for booting in any of the chosen boot mode before, UEFI or legacy, you can skip to step 6.

The UEFI substage is for those installing in the modern UEFI 64 bit systems, while the Legacy mode substage is for those installing in the former/old systems with non UEFI partitions.


0: backup the files in the removable storage, to avoid unnecessary data loss.

1. Goto start, type CMD or Command Prompt, rick click and run as administrator or ctrl + shift + left click / Enter.

2. In the command prompt window, type:

3. List Disk
(Note the drive number of your USB disk)
select disk #
(where is the disk number).

4. Type Clean
NB. This will erase all partitions and data on the USB

5. Type create partition primary

6. Type List partition
NB: If you did not skip actions 1-5, you should see only one partition here, and you can skip to  8.
Note the partition # of the partition and

7. Select Partiton #
where # is the partition #

as can be seen from the image aboove, cause I did a clean command, I have only one partition and the partition is selected by default (the * beside the partition name), so the List partition and select partition is not needed; but for those who skipped to this stage as a result of having multiple partition on their harddrive, they will see multiple partitions and can select the one they wish to format and use as bootable.

8. format fs=fat32 quick

9. active

10. assign

11. Exit

12. double click on the ISO image; or open the iso image with windows explorer (Windows 8 & above) and copy its content directly into the flash, or extract the ISO image with any of your favourite extractors and paste it's content into the USB disk.


If you're installing in a UEFI environment, If it's the new Windows 10, you are done already, if it is a windows 8 ISO image, continue with the additional steps below.

13. if you're installing from a 64 bit environment, goto EFI/Boot directory, if there is a bootx64.efi file in there, you need not worry anymore, you're done else;

14. locate and open install.wim in sources folder

15. copy bootx64.efi to the efi/boot directory of the USB removable disk

16. rename bootx64.efi to bootx64.efi.

17. Grab a drink, you're done.


For those who want to install in a non UEFI environment but the legacy/preUEFI days mode. follow the steps instead;

13.  Goto start, type CMD or Command Prompt, rick click and run as administrator or ctrl + shift + left click / Enter.

14.  type x: where x is the drive letter of the mounted ISO or of your USB removable disk. e.g d:

15. type cd boot to navigate into the x:\boot\ directory

16: type bootsect /nt60 d:
Where d: is the drive letter of your USB removable disk drive.