Q: pop ups safari

Hi, this is my first post.

I have a 2008 iMac that I wanted to update to Mountain Lion. This would enable me to connect my recently purchased Canon 750D and download my images to my computer (the driver software won't work with 10.6.8). So I bought Mountain Lion and installed it after using Time machine to backup my data.

Firstly I found out that Mountain Lion kills Power PC software. This is mainly an issue for my 2004 Microsoft office that my children use for their homework etc (I have 2011 on my Macbook Pro but I try to keep my Macbook and my children separate ).

Secondly, when I opened up Safari I was greeted by constant pop ups, some of which locked up Safari. It was horrible, especially as I had not even gone onto a website yet or downloaded anything. I had simply gone to the Canon website to look for the driver for the Canon 750D. I was shocked as I haven't experienced anything like this before with Mac and going to the same website on the Macbook did not cause the same problems.

Needless to say out came the hard drive with my Time machine backup. But now I can't connect my camera.

I don't mind loosing Office 2004, I can just get a more recent Office but I have paid for Mountain Lion and it seems to come with pre loaded adware. Whats that about? I didn't want to go too recent with the OS on the iMac as it has the maximum 4GB ram and I know that the newer the OS, the more ram it requires to feed it.

Can anyone help cure my adware woes? I doubt Apple will refund the money for Mountain Lion so a fix would be great.

Thanks in advance for your help.