Windows software I can recommend:
– qBittorrent for BitTorrent.
– MusicBee for music.
– MPC-HC + madVR or mpv for video.
– ImageGlass for image viewing.
– Notepad++ for text editing.
– SumatraPDF for viewing PDF files.
– 7-Zip for extracting and creating archives.
– WinDirStat to check disk usage.
– FileZilla for ftp, ftps & sftp transfers.
– Greenshot for screenshots.
– HandBrake for video encoding.
– Exact Audio Copy (EAC) for ripping CDs, also check the main page about EAC.
– KeePass Password Safe as password manager.
– iNFekt NFO Viewer for viewing NFO files.
– HashTab for calculating file hashes.
– MKVToolNix for editing MKV (Matroska) files.
– VeraCrypt for file encryption.
– youtube-dl for downloading YouTube videos. Supports a lot of other sites too.
– RipMe for bulk image downloading. Supports multiple sites including Imgur, 4chan and others.