Some steps to prevent PC virus and spyware.

Nothing is worst than spending a week or more getting rid of a virus. Install an anti-virus software, such as avast. See download.cnet.com for reviews of anti-virus software before downloading, since many are fake or are spyware. It is best to read the reviews of software by users, before downloading to a PC. If there is no review on the vendor site, then do a google search. Good sites for software reviews are download.cnet.com, brothersoft.com and nonags.com .

However, the best thing to do is to prevent virus and spyware.
1) Set cookies on your browser to 'always' prompt/ask. In the beginning, the notifications are a nuisance. However, if the browser remembers your 'safe' list, there won't be a notification when revisiting the site.
When you do this, then you'll be happy that you did. Because you'll see all the sites that have placed cookies on your PC, which take up computer disk space ... another issue. Sites that set cookies are not only the 'parent site', but also all the sites where the ads banners and the graphics are hosted. A big offender is doubleclick.net

2) Set the browser to not allow pop ups, therefore you can decide which sites to display. Again most browsers will have a white-list or exceptions list, so when revisiting the site, you won't be prompted in the future.

3) Use anti-spyware scanner, since it is different from a virus. A virus does actions, such as delete files. However anti-spy will log the user activity. Not all virus software will prevent spy ware. A recommended anti-spyware is MalwareBytes Anti-Spyware.

4) Run an analysis tool like Hijack This or Old Timer Listit, which list all types of inforamation such as programs running in the background such as services, tasks (run once) and start up programs, that may be hidden. Note caution DO NOT use the autofix, rather LOOK up the issue. Do your homework first before removing any entries(esp. registry) or files. Backup the registry (file->export) and create a restore point (start ->accessories->system, system restore , you will need administrative rights for this)


Note that preventing virus and spyware is not a one time deal. Just like dentist checkups are routine, the PC also needs checkups ....
1) Run the ms update monthly, to get the latest security updates. One way to do this, is by using the internet explorer->tools->windows update . Another way is to start->run then type without quotes "wupdmgr.exe –z –q"

2) Download the virus and spyware definitions weekly, if it is not automated. Only definitions are necessary, and not software updates. The definitions are always free and are updated within the software itself.