In most cases it's possible.
Check C:\Users\YOURUSERNAME\AppData\Roaming\DeepOnion and move somewhere the biggest files blk000XX.dat. Then install the new wallet and copy back the blockchain.
Also, always backup your wallet.dat before making any changes and installs.
why it is so? I mean, usually, if I have to update the wallet to the new version, there is no need re-download the whole blockchain from the scratch
and I have updated from the old wallet to the new one, also without it
thank you @kiindje i was thinking about it but in the end redownloaded all. yes i do backup wallet.dat and dumpprivatekey regularly and store them offline, you never know
@Makak4R , that's because i always made clean installs so after backing up all the important things ^^ (plus config with nodes addresses) i wipe all inside the appdata folder