Update:
The unremovable, undeletable Flash super tracking cookie was finally deleted from my hard drive. I did not keep track of how many times I tried to delete it but if i guessed I'd say I tried to delete it approximately 10 times. All 10 attempts were failures. On or around the 11th attempt it was successfully deleted. How'd I do it? No rhyme or reason for the success - it just happened. I did not use a third party program. There was a slight difference with this attempt. During this deletion attempt there were a plethora of other Flash tracking cookies in the #SharedObjects folder that needed to be deleted along with com.jeroenwijering.sol whereas in all the unsuccessful deletion attempts com.jeroenwijering.sol was the only Flash super tracking cookie in my #SharedObjects folder. Was something like that enough to make a difference and was it the reason for the success? I don't know....
And so I highlighted them all figuring that all of the Flash cookies in the #SharedObjects folder (except for com.jeroenwijering.sol )would be deleted to the Recycle Bin. I was wrong.
This time around com.jeroenwijering.sol was successfully deleted along with all the other Flash tracking cookies. I don't know why this time around was successful. There were no OS updates added to my machine. Nor did I do a restart. Like I said, there's no rhyme or reason for the successful deletion, I guess I just got lucky.
Was something running in the background when all approximate 10 failures occurred? I'm not sure. That's a good, intelligent question that needs to be addressed. And it's good speculation that needs to be considered. But since I've been deleting Flash cookies several times every hour of every day for man months now it's safe to say - and reasonable to assume - that I might have had something running in the background when I deleted all the other great many Flash tracking cookies. That's a lot of activity dedicated to deleting Flash files - a daily activity that I started practicing several months ago and that I continue to practice to this day. And my point is during all that activity not once did I ever encounter a problematic Flash file that was undeletable like this little villain was. That just never happened. Which appears to, potentially, reflect a sophisticated level of coding that went into the making of com.jeroenwijering.sol, I speculate.
To answer the other question, I use Avast for antivirus protection. I've been using it for years. Coincidentally, I was just thinking earlier today on how I need to donate money to Avast. I've never paid a cent for their good quality software program. And yet my computer has never been out to the repair shop (I love that aspect, in my book I don't like the idea of a computer user handing their hard drive over to a stranger). Nor have I ever had a Geek Squad-like technician knock on my door. Avast is just one reason why I can cite those two things. And so now I can finally give Avast a grade that is based on years of user experience. This consumer gives them an A grade on their report card. And that is why I need to make a small donation to them. Or maybe I'll consider purchasing their premium virus protection package to reward them for a quality product and to reward them for all the years of free protection they provided me with. If I woke up tomorrow and discovered that Avast has gone out of business I'd be one, unhappy, bummed-out camper.