Your company may not employ the methods above, but may use the ability to remote into one's desktop. Remote Desktop software allows a user, usually an IT person, to remote into a trouble machine and look at it. This allows for the technician to immediately look at the problem without the need to schedule or go up to the department or floor in which the problem PC resides.
For employees, especially those that work from home during the week, this type of software allows them to work on their work computer while at home, at school, or even on vacation. If you're a user of the Windows operating system, you have such a piece of software - the Remote Desktop Connection. If you know the IP address of your work computer or the computer name, you can log in as those you were sitting in front of your work computer. To learn more about RDC and how it works on the new Windows 7, see this Bright Hub article.
RDC isn't the only remote software available. There are third party applications that you can use as well. These are helpful as they are usually geared towards both Windows and Mac users, as well as smartphone and iPhone users. One of these is Log Me In. Log Me In has several versions for use, but there is also a free version that allows you to do some basic remoting.
After signing up with an email address and password, simply install the application on the computer you want to remote to. This will then allow you to access that computer from any other computer, anywhere in the world. Because this uses the internet as a gateway, it's extremely important that you do not share your password.