There's the --db-salvage flag, which has to be applied to monerod.exe from the command line, but it's unlikely that it'll "uncorrupt" your blockchain. However, if you'd like to give it a shot, it's done as follows.
1. Exit the GUI and make sure to close the daemon as well.
2. Browse to the directory monero-wallet-gui.exe is located.
3. Open a new command prompt. This is done by first making sure your cursor isn't located on any of the files and subsequently doing SHIFT + right click. It will give you an option to "Open command window here".
4. Now type -> monerod.exe --db-salvage
5. If that doesn't work, you, unfortunately have to resync from scratch. A resync is easily triggered by deleting C:\ProgramData\bitmonero.
Whilst you're syncing the blockchain using the daemon (monerod.exe), always make sure to exit it gracefully. If you're using the CLI, this is done by simply typing "exit" into monerod.exe. In addition, if you're using the GUI, simply click on the x to close the GUI and make sure to close the daemon as well.
Thanks dEBRUYNE for the fast response! Unfortunately now luck with the --db-salvage flag, so re-syncing, new ssd drive so much faster than my old hdd.
I did not perform a forced exit from the daemon, just left it running on a machine and used the save command regularly -
then when i went back to check it several hours later the daemon had just closed and would not re-initialize, would this just be a glitch? or is there anything i could check to stop it happening again? Cheers
Are you sure your system didn't perform an automatic restart because of some updates?
or is there anything i could check to stop it happening again
Make sure to check whether there are any automatic restarts queued, because Windows will just ignore any program that is running and force quit it.
P.S. An SSD is significantly faster than an HDD with respect to syncing. Thus, if possible, always make sure to sync it to an SSD.