For long-term storage, use QuickPar (PAR2 files) alongside your RAR. If the archive corrupts or you lose the password, the PAR2 file won't help (it doesn't bypass encryption), but it ensures the file integrity is not your problem.
If you have landed on this topic because you have a locked RAR file and no password, you need to understand the landscape before you waste time or infect your computer with malware.
The Verdict Upfront: There is no "magic button" software that can instantly unlock a modern, secure WinRAR archive. The process relies entirely on two methods: brute-force (guessing) or recovery (finding a key). If the password is complex and you have no hints, the chances of unlocking it are near zero.
Here is a breakdown of the solutions available, categorized by how they work and their effectiveness.
Most people use real words or names. Download the "RockYou.txt" wordlist (100 million real leaked passwords). Use a tool like Hashcat to run:
hashcat -m 13000 -a 0 rar_hash.txt rockyou.txt