I Accidentally Deleted Default Credential (which I was useing) is there a way to recover it
You can rebuild the <Default> credential ring using the Credential Ring Wizard.
Start the wizard, enter the name <Default> into Step 1, add the necessary credentials from the stored collection in Step 2 and Step 3 of the first screen, and then map those credentials to the domain, workgroup, and WSUS server resources they were previously mapped to. If additional rules for OU, Computer, or "Directory Only" were present you can add them at that time also.