Make sure you run up to date Anti Virus software and Anti Spyware software and use a personal Firewall. Anti Virus and Anti Spyware software is intended to ensure that your PC stays "virus free" and does not have any malicious or unwanted programs running on it. There are several products on the market which can be updated by downloading from the Internet; searching the Internet using a search engine with the search text 'Anti Virus Products' will give details of several of the products available many of which include Anti Spyware and personal Firewalls, these are often referred to as "Internet Security Suites".
We recommend you run the latest Internet Browser - this should be the latest web browser appropriate to your Operating System (e.g. Internet Explorer 8.0 for Windows Vista). Further details should be obtained from your Browser supplier; for the majority of users this will be Microsoft's Internet Explorer (IE) Browser. Further details can be found at the Microsoft website. For other Browser users (e.g. Firefox or Safari) details can be found at the Firefox website or the Safari website, but again you should use the latests versions of these.
Make sure you keep your computer's Operating System and Browser (e.g. Windows Vista/XP and Internet Explorer 8) up to date with the latest security patches - keeping updated with the latest patches will help prevent home PC disruption from software vulnerabilites. Ideally, set your system to receive these updates automatically. Further details on this and on other home PC protection including Anti Virus, Anti Spyware and personal Firewalls can be found on the Microsoft website.