Tech Esoterica

This is a pile of quick-reference tech concepts. They’re effectively trivia, but very important unless you work in the industry.

Slow Computer Fixes

NOTE: Avoid the following:

  • Registry cleaners
    • A registry is plaintext and takes up very little space.
    • Modifying the registry can permanently damage the OS, even with Windows Update.
  • Most third-party system cleaners
    • Most of them do what Windows’ Disk Cleanup already does, alongside the above-mentioned registry cleaning.
    • They’re usually adware or tracking user data you probably don’t want.
  1. Just to be sure, run an antivirus scan.
  2. Check for any running tasks, and sort by CPU, memory, and network use to find what’s using them the most.
  3. Turn the power settings to the max (in Windows, “Always On” or “High Performance” setting for plugged-in).
  4. Check the interior for dust and blow it out with an air compressor.
    • Canned air has chemicals that can corrode motherboard circuits.
    • If possible, apply more thermal paste between the CPU and its fan.
  5. Check that there’s enough hard drive space (especially in C: drive in Windows).
    • Empty the Recycle Bin.
    • (in Windows) Run Disk Cleanup with Administrative permissions.
    • Use a file size checker like WinDirStat for large useless files.
    • Uninstall programs you don’t need or haven’t used in more than a year.
    • Run CCleaner’s or System Ninja’s general clean (but avoid their registry features in Windows).
  6. (in Windows) Run Disk Defragmenter and schedule it to run daily or weekly.
  7. (in Windows) Disable Startup items (in msconfig or Task Manager) and tasks in Task Scheduler.
  8. (in Windows’ services.msc) Websearch and disable unnecessary Windows services.
  9. (in Windows command prompt) Scan the system:
    1. sfc /scannow (scans system files, re-run until no issues)
    2. chkdsk /r (checks the entire disk)
  10. (in Windows’ Powershell terminal) Check the system image:
    • DISM /Online /Cleanup-Image /RestoreHealth
  11. Swap out Chrome web browser for Brave or Firefox (which consume less memory/CPU).
  12. After all this doesn’t work, upgrade it:
    • A new SSD hard drive, if it’s a HDD (the easiest upgrade, assuming it’s not a laptop).
    • A better CPU (it must match the chipset of the current processor).
  13. If you need a new motherboard for better parts, get a new computer for your purposes.
    • Use the old computer for a dedicated side-project that doesn’t need heavy use.

Network Debugging

  1. Ping a known local IP address: ping
  2. Test telnet access to that local IP (failure is secure): telnet
    • In Windows, enable “Telnet Client” under Programs and Features before using.
  3. Nmap the LAN side of the modem: nmap -v -A -p 1-65535
  4. Check DNS settings, manually override with a known DNS provider.
  5. Repeat for a known internet IP (e.g.,