I run a PC security web site called pcsecuritynews.com that has some pretty extensive FAQs... unfortunately, we are in the process of moving the site to a new server and our FAQs aren't back online yet.
However, I did a bit of research on your behalf and found out that wtoolsa.exe is pretty hard to get rid of. It looks like you're going to have to remove it manually and do some stuff to your Windows registry to fix it once and for all.
Fortunately, there is a handy program out there called HijackThis and some great forums to help you use it. Here's a link to where you can download it:
It's the seventh item on the list under Detection and Removal (scroll down past XCleaner).
Here's a tutorial on how to use it: http://www.tomcoyote.org/hjt/
Basically, you run it and it detects anything suspicious floating around in your Windows registry. Then you post a log on one of the many forums that are devoted to HijackThis and smart people who read the forums will tell you which entries you should remove.
Before you use HijackThis, I would recommend running anti-spyware programs. No anti-spyware program is perfect; in addition to Spybot and Ad-Aware, I would get the trial versions of PestPatrol - http://www.pestpatrol.com/ - and SpySweeper - http://www.webroot.com/ - and run them too. The trial versions are the full version except you can only download spyware definitions once (to get updates you have to buy the software). Between the four of them, they should find anything that is possibly detectable by an anti-spyware program. Don't restart your computer until after you've run HijackThis and figured out what to remove from your registry. Probably there is an entry in your registry somewhere that makes the spyware re-install itself whenever you reboot.
Please let me know if you have more problems, I am happy to help.