What it should tell you is that you need the PC's IP address and the password that you create when you set up TightVNC. It's clear enough that you need to add a new host, but you then are presented with fields asking for a Computer Name and Authentication. So I dutifully downloaded TightVNC on my PC, ran it, and then ran Desktop Connect on the iPad. For Windows PCs, it only tells you that you need to download a VNC server, saying that TightVNC had been tested and works with Desktop Connect. I haven't tried it on our iMac yet, but the documentation the app delivers is a lot more extensive for Apple computers than Windows systems. It uses RDP natively, but can also work with VNC servers. I had heard about Desktop Connect on a few other sites, and paid the $11.99 "introductory" price to download it to my iPad.
My fellow ZDNet blogger Jason Perlow has discussed one RDP solution here, but since my primary computer runs Windows 7 Home Premium, I needed to go the VNC route. Some are able to use Remote Desktop Protocol (RDP), such as Professional versions of Windows 7, while others need to use Virtual Network Computing (VNC). There are a few apps that make it possible to connect to a Mac or a Windows- or Linux-based PC, falling into two camps. You might forget to email yourself a document on your desktop hard drive that you want to read or work on using the iPad, or you might want to play a PC-only game that doesn't rely on split-second fragging (hypothetically speaking, of course). I can see the argument that using the Apple tablet to spend an extensive amount of time dealing with a remote computer's interface would be challenging, but I can think of a few reasons you'd want the capability. Some people think the idea of controlling another computer through an iPad is a ridiculous idea-why wouldn't you just get a laptop and then it's not even an issue.