I'm with you about demographic info. I know they want to customize the junk mail they send us, but I don't have any use for 99% of it. I see all the ads I need and then some on TV, in the paper, and online.
Now regarding registry cleaners, avoid all of them. They do no good and can cause problems that're difficult to impossible to diagnose and correct. We used to find them beneficial before Windows 2000, but since then MS has changed the way they handle the registry such that these so-called registry cleaners are not only not needed, not helpful, and they can only cause problems.
After re-reading this, I realize that I've rolled together two problems - privacy and slow computer. I think they are related, though.
I have an HP tower, P6000 series with Windows 7 and IE 8 on it. It's gotten really hinky. By that I mean it seems to "get lost" while it's doing something. I download a spreadsheet from my website regularly and it's getting where it will just sit there with that little spinning thing and take forever to download the file and it's not a very big file. (Similar problems are occuring while not working online or downloading from the web.)
I regularly use at least three sites that are really agressive with ads, so I'm assuming I'm loaded up with competing cookies and dregs of leftover programs, etc.
I ran AVG's tune-up program, and it seemed to help a little. It said 30 day free trial, but it let you run the program once. I don't mind paying for a program, but I don't want to buy AVG because of the demographic information they require to register your product. (I lied the last time I bought from them and then couldn't remember what I said, so couldn't update it.) I mean, really, why do they need your home address if you're downloading the program and paying by paypal? What difference does it make to them if I'm 20 or 80? Does every company have a sideline of selling demographic info?
There are hundreds of those programs out there. How do you know what you're getting? It seems like every program out there wants to know your address, age and sex. I don't do anything on the web I would be ashamed of my mother knowing, but I also hate that feeling of being watched. (I'm in the diet food business and 8 out of 10 pages I view seems to have a Freshology ad. )
I realize system restore would work better to clean my system, but my backups are not that wonderful and every time I do it, I end up losing something. Also , it doesn't help with being watched.
(Ok, so I'm a nut, but it's creepy the way they are tracking you.)