Test your skills
While surfing on the webs, I oftenly find the notification "Your computer may be infected'. What does the notification means?
Check your web browser if Norton Safe Web is installed on it. If this add-on is installed on the web browser you are using this will protect your computer from any of the web sites that might harm your system. This add-on scans every web site you visited and if that web site is listed among the harmful and dangerous sites it will automatically block you from browsing the web site and will display a warning in your whole screen.
But if the alert is not coming from this add-on, try checking your system for possible virus infection. Update your antivirus then run a full system scan on your whole computer. Be sure to scan the folder \System Volume Information which is located in the root of every drive. This folder is the favorite target of most Trojans. This folder doesn’t normally appear in your Windows Explorer and to make it visible you need to make some changes in the Folder Options to view hidden files and folders.
But, on the other hand, if that alert is from the web site you visited, just ignore it because it’s only an advertisement for some antivirus brand.