ExeWatch lets you know visually and audibly every time an executable comes on board; extremely light.
WinPatrol monitors your startup programs. Autoruns is a somewhat different program, not for running realtime, that you should also get.
In fact, get the Sysinternals Suite which also gives you Process Explorer, a great way to monitor your running processes.
Another fine free suite, having a huge number of lightweight programs, is NirLauncher. It includes BlueScreenView. Also get WhoCrashed for blue screens.
System Explorer is a good task manager with a toolbox of other goodies.
Glary Utlities gives you more than CCleaner.
MasterSeeker is the best file and folder search problem I've found. Love it! It has a shredding option.
The best registry search programs I've found are freewares Registry Finder and Registrar Registry Manager.
4K Dowloader grabs videos and audios other programs won't.
Jarte is a superior word processor.
ArsClip is a quite good clipboard manager.
Check downloads with Virus Total Scanner, or if it doesn't work, Virus Total Uploader.
HostsMan for managing your HOSTs file.
Get LastPass or something similar for Password manager/secure notes/autofills
Remember that virtually all the most prestigious paid AV companies offer on their websites free on-demand scanners that will use the same signatures as their premium products. Not all will actually remove what they find, but if they show you the problem, you can find another program that will or do it manually.
I recommend Revo, IObit, and Geek uninstallers, all three. One gets what the other misses.
EMCO MoveOnBoot for getting rid of stubborn files, FileShredder for irreversible deletion.
PeaZip for compressed files and for compressing files
Since you want a Chromium family browser, consider Comodo Dragon and SlimJet.