Mount my old HDD as bootable USB

Hi Experts,

please can anyone tell me how to mount/load my old HDD (which I have just taken out of my machine) as bootable USB drive. I basically want to be able to boot from my old drive instead of the newly installed drive. I don't want to have to remove the new drive and put the old one back in, just to access a couple of files. I have put the old drive in a USB caddy and set the boot sequence to USB first, but, when I try to boot it gives me the message "No boot sector on USB device" then proceed to boot from the internal HDD.

Help with this is greatly appreciated.
Ian LeasonAsked:
Who is Participating?

[Product update] Infrastructure Analysis Tool is now available with Business Accounts.Learn More

I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

Gareth ChamberlainIT ManagerCommented:
The utility to write Windows 7 boot sectors - bootsect.exe - Within the Windows Recovery Disk

"bootsect /nt60 c: /mbr"

This writes a bootsector in Win 7 format (im assuming you are using Win7) to c: and Windows MBR to disk where DOS_drive (partition) "c:" is placed.

Windows 7 install (also StartUp Repair) usually writes PBR to active partition and to partition where Win 7 system is installed. (active and installation partition can be different partitions !)

"bootsect /nt60 ALL /mbr"

This writes Win 7 boot sectors to all Windows partitions (NTFS, FAT32) excluding "foreign" Linux partitions. MBR is written to first disk.
Ian LeasonAuthor Commented:
so can I safely use the bootsect without it losing anything on my drive?
Gareth ChamberlainIT ManagerCommented:
If you are not using it as a fresh install (Nuke and Boot) then i would recommend using this program which has helped me in the past 

Acronis True Image 2019 just released!

Create a reliable backup. Make sure you always have dependable copies of your data so you can restore your entire system or individual files.

Ian LeasonAuthor Commented:
the new drive in my system is a fresh install and that's fine, but I need to access my old drive exactly as it was prior to removal. So I need to ensure whatever I do doesn't corrupt any of the files.
The best way to get files from another hard drive through USB is to use a less than $30 USB/Sata adapter which can be purchased anywhere and comes in handy more than once.
Ian LeasonAuthor Commented:
I need to mount the drive as an OS, I already have the drive in an external caddy. I am unable to access the files I need simply through Windows explorer etc hence the reason I need to use the drive as if it is installed as the main OS.
If you want to boot your old OS that is still on the disk via USB, and that OS is Windows, you can't do that as it isn't supported. Windows needs to boot from internal disks unless it is Windows To Go, which is only available in the enterprise versions of Windows 8.x and 10, and it has to be setup specifically for the USB disk/stick.

For Linux, there should be no problems with most distro's, just change the BIOS's boot order to start from the USB disk first.

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
Ian LeasonAuthor Commented:
That is eaxactly what I was trying to do (my OS is Windows 7) that explains why nothing I did would work. Thank you for your help
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Storage Hardware

From novice to tech pro — start learning today.