Its similiar like my oldest computer. Did you tried Arch(With KDE)? It s little hardest to install but after install result is powerful distro but if you don t want Arch i recommend install Elementary OS or Deepin.
IMO: Linux should not be defragmented, simply, the act of saving a given, "measure" mass memory to see if it can contain the file, otherwise, like all Unix, automatically diverts another section of memory.
In one case you must defragment: if your system includes a Windows installation, and you have your data in a partition to which access both Win and Linux.
open vpn and CG is goodBIG UPDATE:
OS: Windows 7 Home Premium
Real-Time AV: ESET SMART SECURITY
Firewall: HW Cisco
DNS: Norton DNS
On-demand scanners: MBAM. HitmanPro, Zemana AM
Anti-Keylogger: Zemana AL
Photo Editor: Adobe Photoshop CS6
Mail Client: Mozilla Thunderbird
Web Browser: Mozilla Firefox(main), Google Chrome(IBaking(my bank have page written in Flash))
Privacy tools: PrivaZer, CCleaner, BleachBit
Video Players: VLC & MPC
Music Player: Winamp
Auto Backup to External HDD and Home-made cloud.