Please explain the problem in detail. What happens? What is/are the exact error message(s) ?

I bought a new PC and changed from Windows 7 to windows 10. The technician loaded my old data to my new PC. When I opened my web browser all of my bookmarks and saved passwords were missing.

It's possible the browse could not find the old profile, or there was a problem with the old, and created a new profile.

Look on your desktop. Do you see a folder called; Old Firefox? Look inside. Look for the folder with the latest creation date.

https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update

https://support.mozilla.org/en-US/kb/how-run-firefox-when-profile-missing-inaccessible

http://kb.mozillazine.org/Profile_folder_-_Firefox#Navigating_to_the_profile_folder

https://support.mozilla.org/en-US/kb/profile-manager-create-and-remove-firefox-profiles

https://support.mozilla.org/en-US/kb/back-and-restore-information-firefox-profiles

Type about:profiles<enter> in the address box. How many profiles are listed? How many should be there? Also, open the profile folder in your file explorer.

https://support.mozilla.org/en-US/kb/recover-user-data-missing-after-firefox-update

Note that the Firefox profile folder with your personal data is in a hidden location in "AppData\Roaming", so it is possible that the technician didn't copy this data.

Do you still have the old computer or at least have access to its hard drive ?

• https://support.mozilla.org/en-US/kb/recovering-important-data-from-an-old-profile

i have the hard drive but no way to use it.

The old hard drive could be plugged into the new system and used as an external drive. As long as the drive itself was not damaged/has problems.