Oracle Virtual box extensions install fails with VERR_ACCESS_DENIED due to McAfee

Installing Virtual Box 5.1.2 extensions on windows 10 failed with this error:

VBoxExtPackHelperApp.exe: error: Failed to rename the temporary directory to the final one: VERR_ACCESS_DENIED ('D:\Program Files\Oracle\VirtualBox\ExtensionPacks\Oracle_VM_VirtualBox_Extension_Pack-_-inst-4288' -> 'D:\Program Files\Oracle\VirtualBox\ExtensionPacks\Oracle_VM_VirtualBox_Extension_Pack')

After seeing several people on the net pointing to the antivirus, I disabled the McAfee real time virus scanning that came for 1 year with my Dell PC:

1. Right click System Tray McAffee LiveSafeIcon
2. Change Settings > Real Time Scanning
3. Turn off
1. Leave In 15 minutes

Then I reran the extensions installer and all went well.

Free Microsoft Anti-virus coming

Microsoft will add their Live OneCare consumer anti-virus (subscription now $50/year) as a free offering, codenamed Morro (after a Brazilian town), from the second half of 2009 on.
It is difficult for MicroSoft to sell stuff that corrects security issues within their own products.
OneCare had less than 2% of the antivirus market. This is expected to rise now :)
Morro will be based on Micorosft Forefront client security and is expected to merge with the existing free Windows Defender (anti-spyware).
Meanwhile MicroSoft continues the Forefront Security Suite, their centrally managed enterprise security offering.