My pc is moderately quondam and I must been told that having anti spyware installed on it drive past it it down close to at least 25%. I am philosophical what is the lesser of two evils! No anti spyware or invasion alongside spyware! As I am objectively unripe to computers I am at the moment being fairly cautious fro downloading things. Counsel much appreciated. I am on XP proffesional.
You can see at download dot com how many popular Ad-Aware and Spybot Search & Destroy are. And I would ignore the conflict message between the two. I've used both for years. If you want to use a more powerful one, there's a trial version of CounterSpy. If you really don't want to install anything, then you could always try McAfee freescan. But, that's more for viruses. There's also AVG which is free for viruses.
I have no idea what "moderately quondam" is, but if you are on ET and you don't have active spyware/anti-maleware you are making a huge mistake! I use NOD ESET. It come highly recommended by industry professionals. Good luck.
spybot search and destroy & ad aware of course, both are offered in english, so they may not be appropriate for you
are you using a firewall software program ? you should be, there are several free ones available an antivirus software program is more important imo than spybot etc free Avira: http://www.free-av.com/