I don't think I have any spyware installed.
Should I? Won't the virus checker deal with that?
No ~ cos it ain't a virus. Spyware is to stop people tracking what you do. Companies use it rather like Sainsbury and their cohorts use Nectar Cards.
Don't tell me ~ you thought Nectar was all about rewarding your loyalty and nothing whatever to do with sophisticated research into buying habits enabling targeting of offers etc.
Lavasoft (despite Berek's allegations) is very good and also free for home users. The only fault I have with it is that you have to (a) update it manually (ie you have to ask it to update as it doesn't do it automatically but it does issue the odd reminder AND (b) You have to instruct it to scan (it cannot be set up to do that automatically either)
The reservation above only apply to the free version. Pay for it and it comes with bells and whistles but how hard is it to scan once a week .... you can work whilst it goes on in the background. They recommend that you quarantine any "serious" threats in case you delete something you may want later but I gave up doing that and simply delete them anyway (as does everyone else I know who uses it)