Welcome Ron Wynkoop,
I'm sorry you're dealing with this, especially with important rental information on the PC.
To narrow this down, could you confirm:
- Are you signing in with a personal Microsoft account (Outlook.com, Hotmail.com, Live.com, etc.) or a local account?
- When you start the computer, do you see a message asking for a BitLocker Recovery Key or mentioning drive encryption?
- Is the old computer still able to start Windows, or is Windows no longer loading?
In the meantime, please try this quick check:
- On another device, sign in to your Microsoft account at Microsoft's BitLocker recovery key page: https://account.microsoft.com/devices/recoverykey
- If a recovery key is listed, compare the Key ID shown on the locked computer with the Key ID on the website.
- If they match, enter the recovery key to unlock the drive.
If the drive is BitLocker-encrypted and the recovery key is not available, access to the encrypted data may not be possible. However, let's first confirm whether BitLocker is actually involved before moving further.
Also, for your privacy and safety, please do not post phone numbers or email addresses in the public forum.
I look forward to your reply with the answers to the questions above.