Virtual drives, how to use

I have only just discovered the existence of virtual drives. VMPlayer, Virtual box (??)
I am not sure how they work (or their limitations)

1. Which one to use (if there are others) ?
2. Are they commercial or free (the only links I can find do not say) ?
3. How do I use a virtual drive (again web pages and Wiki are for the converted) ?

Currently I download files (test with VirusTotal, desktop AV and anti-malware), install and use them. If not what I want I uninstall.
Occasionally crap ware is installed and sometimes can be a pain to remove. (A lot of wasted time)
Restore points and "imaging(?)" I have not used -- yet! :blush:
(I know how to make a restore point but not how to apply it. I am concerned about the loss of data files when I apply a restore point.)

So far web pages point to testing OS in virtual-drive, but I would like to test EXE downloads in a safe environment.
Should ZIP files be extracted in a virtula drive (safe environment)
I understand virtual drives quarantine what is in the VD until I instruct to delete or save.

Would appreciate any help or advise :1confused: :smile:

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SPECS:
Toshiba Satellite C665
OS:= Windows 7 Home Premium (32-bit), sp1 (Build 7601) OEM
UI:=Classic Shell Start + Classic Explorer