Typical signs that your PC may be infected with spyware include
“1. You notice new toolbars, links, or favorites that you didn't intentionally add to your web browser.
2. Your home page, mouse pointer, or search program changes unexpectedly.
3. You type the address of a specific website into your web browser, but you're taken to a completely unrelated website.
4. You see pop-up ads, even if your computer isn't connected to the Internet
5. Your computer suddenly starts running slowly. Not all computer performance problems are caused by spyware, but spyware can cause a noticeable change.”
How to tell if your computer is infected with spyware and more importantly how to remove spyware from your computer