While Best Buy and others charge for their virus removal services, Microsoft Stores now offer this service for free. Simply schedule an appointment with your local store, bring in your computer, and they’ll do the rest. The only requirement is that it’s a Microsoft Windows PC.
If going to the Microsoft Store isn’t an option, they do offer online consultations, but that’ll set you back $99/hour.
NOTE: I can not attest to the quality of any of these removal services. My hunch is that they’re fine for more basic tasks, such as using System Restore to revert the system to a state prior to infection, and running various tools to detect and remove known threats, but more complex threats would likely be met with a backup and re-installation of the OS and you might be on the hook to reinstall any applications. Even so, this is a worthwhile option for many people.