If it's too late and you already have problems, get a friend to download Malwarebytes and put it on a flash drive for you, then install and run it on your computer.
- Download and run ATF-Cleaner (no installation required) to first clean out all the junk files sitting on your computer that will slow down the next programs listed.
- Download and install other browsers besides Internet Explorer. We recommend Firefox, Chrome, Safari or Opera. It helps when something targets Internet Explorer specifically.
- Install an antivirus or at least make sure it's up to date. We recommend: AVG, Kaspersky, Microsoft Security Essentials, ESET and, recently, Sunbelt Vipre. McAfee and Norton are better than nothing, but not much. :)
- Install an anti-malware or at least make sure it's up to date. We recommend: MalwareBytes, SuperAntiSpyware, Microsoft Security Essentials and aSquared.