You should really be swearing on the SpywareDoctor forum.

This is a well known limitation of SpywareDoctor, and one of the reasons it's not much recommended here (although you will often see it recommended on a lot of sponsored search results.) Apparently it is fairly good, but I've heard reports also that it is fairly bloated.
Now to the recommendations.
zellist had a good one. Get it
here.Also good,
SAS (get the free edition.)
Either program has a one time payment option if you want resident protection activated, very good value IMO, but either free version works very well indeed as a demand scanner.
Did you ever get Spybot working? It's a pretty good old workhorse, honest as, and still under development. "Mirrors" just allow one to download it (and updates) from a large choice of areas. Download speeds differ from mirror to mirror, depending on where you are. Generally, choose a mirror close to your geographical location, as the internet cable flies.
Avast will run happily with Spybot, and/or MBAM, and/or SAS installed. You must not try and install another AV with Avast present, however.
Now, your reference above to "7 something" is probably Internet Explorer 7. This browser is out of date and should be updated to #8, available through Windows Updates.
Keeping Windows up to date is highly recommended.
Also I'd be inclined to install and run
Secunia PSI (it's the "download" button near the top left of this page). This will scan and report on the status of most of your installed software, not just the Windows components. Especially important to keep Java and Flash players up to date, but really anything for which a vulnerability has been discovered and patched.
[
edit] Get rid of SPyware Doctor by going to "control panel>add/remove programs" and once the list has loaded, select Spyware Doctor and uninstall it. A reboot will probably be needed after this.