It is a scam!
First step before we get serious, reboot into Safe Mode. I assume you are using Windows but you don't say and you don't say which version of Windows.
When you restart the computer and just before Windows begins to load, start pressing the F8 key gently once a second. In time you will see a list of options of which Safe Mode is the top one. If that is selected, press Enter. If it is not selected, use the arrow keys on the keyboard to select it then press Enter.
Wait for Windows to load into this diagnostic mode and when it does, head over to the Control Panel, then Add/Remove programs, (XP and below), or Programs & Features, (Vista and Win 7), and uninstall it from there.
Tell us how you get on.
I signed up for a "free" scan by PC Cleaner Pro and now I can't uninstall it.I get two signs on my pages warning me that I have thousands of errors on my computer. If I try to uninstall PC Pro Cleaner I get another big sign that tells me to call by phone and they will fix my problems. I did this and all they wanted to do was to sell me the service thet I do not want, and they wouldn't uninstall it. I can't get rid of the big sign unless I turn off my computer and sign back in. The smaller WARNING! sign stays on the screen. HELP!!! Any help will be greatly appreciated. Thanks.