how to install Windows 10 with Hiren's Boot CD by mounting an ISO file

I have started my laptop via Hiren's boot CD. There are two partitions in my HDD and one of them has my backup and other stuffs and a Win10 ISO file.

I have mounted it and tried to install Win10 but it said something like "this disk has MBR partition, only GPT can be installed on EFI systems". Now I know one the solution is using diskpart to convert my hdd to gpt but I can't because as I said I have my backups on the disk.

I have a 1 TB external HDD and I also tried to burn iso file on it via Rufus (with MBR), but then I got "Undetermined error while formatting"

I have tried using diskpart to make my 1TB bootable then copy extracted iso file into it: also failed while booting: "no operating system has been found"

I have also tried ultraISO and other bootable driver maker apps, same result: error while formatting...

Now: I can't convert my HDD to GPT

I have a 1 TB external HDD

I have Hiren's boot CD

I have a Win10 ISO file on my second partition of my laptop's HDD

So please, can someone tell me a solution?

1 Answer

Since you have a 1TB external drive, my suggestion:

1. boot to Hiren
2. Connect the external drive
3. Copy all your data from the internal HD to the backup drive Then remove that drive safely. 4a) Burn the Windows ISO to a DVD 4b) Write the Windows ISO to a bootable USB
4. optionally use Hiren to delete all partitions on the internal HD
5. Install Windows 10 from DVD or USB If skipped 5, remove all partitions and install cleanly