If you don't have your account synced on another device or your data backed up, you will have to start over. Sync is not a back up service. It also depends on how you reinstalled. Did you just reset Windows and keep your files? If so, then there should be a folder under the c drive called [https://support.microsoft.com/en-us/windows/retrieve-files-from-the-windows-old-folder-f668ada4-701b-204a-73c3-952bc5ceb1c8 Windows.old] If not, then you will have to start over.