That depends on how you deleted the browser. Can you give details?

Look on your desktop. Do you see a folder called; Old Firefox?

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

Type about:profiles<enter> in the address bar. How many profiles are listed? How many should be there?

Along the lines of Fred's first question:

When you use the built-in Firefox uninstaller, it does not remove your data. This makes it easy to change versions because when Firefox reinstalls, it recognizes and uses your existing data. (This assumes the same Windows user, since different users have different profile folders.)

However, if you use a third party uninstaller or cleaner, or if you restore/refresh Windows, then you risk data loss.