I found an old disk wallet.dat but

[bad man]

how to fix


Bitcoin Core - Warning
Warning: Error reading C: \Users\C
\AppData\Roaming\Bitcoin wallets\ii\wallet.dat! Transaction data may be missing or incorrect. Rescanning wallet.

[Findingnemo]

What comes to my mind after reading this is when people buy wallet.dat file that shows balance but can't able to decrypt it.

Did you really find the file on the old disk as you claim or someone sold that to you?

[BitMaxz]

Run Bitcoin Core with -rescan but before doing anything else about the wallet.dat file you found please make a backup first so that if you mess up with the first recovery attempt and it becomes corrupted you have a backup copy.

To run Bitcoin Core with -rescan just edit the Bitcoin Core shortcut file and paste the "-rescan" under the target and then apply.
Check this image below



Run the Bitcoin core and let's hope it fixes your issue.

[bad man]

What comes to my mind after reading this is when people buy wallet.dat file that shows balance but can't able to decrypt it.

Did you really find the file on the old disk as you claim or someone sold that to you?

No My friend, there's no lock, it's just a file, but I can't read it.

[ymgve2]

Was this a deleted file that you recovered? Deleted files can sometimes be corrupted, or just a fragment of a completely unrelated file. Have you tried opening the wallet.dat in a hex editor to see if it actually contains something and isn't just full of zeros?