maintenance/security/utilities:
CCleaner
https://www.ccleaner.com/ccleaner/
CCleaner is the number-one tool for cleaning your PC.
It protects your privacy and makes your computer faster and more secure!
Malwarebytes
https://www.malwarebytes.com/for-home/
Malwarebytes doesn’t just find threats like malware and viruses, it also finds potentially unwanted programs that can slow you down. Malwarebytes protects all your devices and personal info from threats, so you can shop, play, and connect without a second thought.
KeePass
KeePass is a free open source password manager, which helps you to manage your passwords in a secure way. You can store all your passwords in one database, which is locked with a master key. So you only have to remember one single master key to unlock the whole database. Database files are encrypted using the best and most secure encryption algorithms currently known
grepWin
https://github.com/stefankueng/grepWin
grepWin is a simple search and replace tool which can use regular expressions to do its job. This allows to do much more powerful searches and replaces.
FreeFileSync
FreeFileSync is a folder comparison and synchronization software that creates and manages backup copies of all your important files. Instead of copying every file every time, FreeFileSync determines the differences between a source and a target folder and transfers only the minimum amount of data needed. FreeFileSync is Open Source software, available for Windows, macOS, and Linux.
WinMerge
WinMerge is an Open Source differencing and merging tool for Windows. WinMerge can compare both folders and files, presenting differences in a visual text format that is easy to understand and handle.