Some Spam Mail Carries Computer Worms

I had been looking for a fun game to play online.  After doing a search I found a few that I thought that I would like. I signed up with one of the game places and went to my email to retrieve the information that they promised to send.  I should have had an antispam program installed on my computer before signing up with anything.  Once I clicked on the link for the game, a notice came up saying that I was infected.  I had to take my computer to a technician to get rid of the worm.  It was a real nightmare and really expensive to get my computer fixed.