$450.00 wow I'm not sure I would ever spend that much money on a vid card! But all I do is edit video almost nothing else. I have found the video card isn't as important as the speed of the CPU but neither is ram either. My Win 7 64 set up has 6 gb ram and a couple of TB's of hard drive space. I have a lower end ATI Raedon card HD 3600 but ...

It still sounds like a Video Card issue. Do you have a different card you can try just to rule it out?

Which input are you using and have you tried a different cable?

I am using Win 7 64 bit and it works here. Are you clicking on the video clip you want to place the effect on?

You should spend some time looking up some training aides. It will help gain much needed knowledge and make your life easier. Do a search in this forum as there are lots of free tutorials online. You can also search for help with issues like this as it is discussed almost every week..........

This won't help right now in your situation but next time consider using more than 1 drive. If your capture folder your project folder MediaAV and render folder is on a separate drive then if you have a virus or even lose the system drive, you can install a new drive and open your project easily. Some use a separate drive for capture and render ...

''Liquid only seems to expect a 4x3 file when encoding so I wound up with a letterboxed version.'' this is not true your timeline properties dictate what Liquid expects. is it possible your timeline properties are not correct?

Format factory has been a suggestion on this forum as well as Super video converter they are free do a Google search and give them a try...

you need to delete all of your render files and let Liquid re-render your timeline......... did you do a search? this has been discussed many times in the last year........

Stay with an Intel based system and you will be fine. Core 2 dual or quad core is fine. It is really hard to go wrong right now and with prices as low as they have ever been I think your wasting your time doing anything else. You can choose to wait but its a waste of time as there are lots of users who have newer systems using Liquid that work ...