How do trial programs know they have been on your computer before?

This is something I have been wondering for a while. If you have a trial program installed and your trial expires, then you un-install the program and re-install the same trial, it knows that it has been on you computer before and prompts you for a license key. How does it know even if all traces of the program have been removed from your computer? My best guess is when a trial is installed some information unique to your machine is sent to the publisher, when you try to install it again it checks this database for your machines ID to see if you have already had it. Also please don’t misinterpret my post, I am by no means looking for a way to bypass this, it’s just strictly curiosity.

 

I am guessing it records the Computer's IP address, name, etc.

What I am wondering, is just how knowledgeable and extensive the vendor's software base is. Say, for example, you "trial" a product that offers a "30 day trial".....but you only use it for 20 days and then unistall it. My guess is that even though TECHNICALLY you should still have 10 days remaining, it would not allow the download for any trial because "it had been downloaded PREVIOUSLY". I would be really interested to know if anyone has unistalled the product before the trial period was up, had some remaining time, and then tried to download the trial again at some other point, to see if they received their "remaining" trial period. My guess would be that unless they reinstalled during that initial 30 day period (and even then), it's probably history......

 

It's usually a little something hidden in the registry. I don't like leftovers (except from the dinner table) so I use Total Uninstall for almost every single program I install. TotalUninstall 2 is still free.
http://www.martau.com/archives/tun235.zip

 

"a little something hidden in the registry"!!!. I doubt it. because you can backup regidtry just b4 you download the trial, when trial period finishes and you rollback the registry. You still wont be able to try it again.It must be some thing hidden in Windows folders/files

 

IP address remains the same after Format/install, So it cant be that

 

"It must be some thing hidden in Windows folders/files"
Try TotalUninstall... it always works here.

 

Hi, even if you use something like the very useful Total Uninstall, this will not be enough to fool the trial version. Nor will also doing a Reg clean with another fine product like RegSeeker.

Even if you also do a Windows search through your PC for any thing to do with the software etc, and get rid of whatever you may find, you still won't be able to run the same App again. And of course you're not supposed to, that's the whole point of it being a trial version.

From what i can gather, at some point after installation, a little piece of code is stored away that is looked for, and referenced to on installation if found. This could be anywhere on a PC, and is usually named in such a way as to be unconnected to the App, on purpose.

Software companys and staff do like to eat etc, and also have bills to pay, so more power to them for being able to achieve the time outs etc.


StevieO

 

Totalunistall is not better than registry backup. the later wont be able do any thing so is totaluninstall

 

Its definitely something on your compure as ive had a load of trial programs that wont let you install them no more.

Then after format i can. (and ive allowed them outbound connections too) ala spysweeper, was the main one i used to do it over.

So its definitely something on your computer.

For me if i was unistalling a trial of WinDVD. I would uninstall then do a reg seeker search for WinDVD (youll be amazed how many entries you find of your seemingly uninstalled app)