Hi Jeff,
I believe your rendering difficulty is your low PC RAM and slow harddrive. I do not observe VideoPad rendering any slower than a competitor’s video editing program Pinnacle Video Studio Plus, which has been on the market for many years, and a favorite among hobbyists.
The key to your problem is stated on the VideoGuys website (first URL below) in the paragraph containing “your main system requirement is: 9+ megs per second sustained throughput for real-time… For HD editing you will need even more!” I believe HD takes 4 time 9+ or about 40 megs per second. Harddrives move data about 10 time slower than RAM, so you can either install 8 Gig of RAM, and a 64 bit operating system such as Vista 64 or Windows 64, or run a SATA Raid drive with 4 physical drives or a solid state drive.
If you are skeptical about what I am writing here, I suggest you read what the experts have to say on the subject. Read the webpages at the following URLs. https://www.videoguys.com/Guide/E/Videoguys+System+recommendations+for+Video+Editing/0x4aebb06ba071d2b6a2cd784ce243a6c6.aspx
http://www.brighthub.com/multimedia/video/articles/87956.aspx
The bottom line, video editing is the highest data rate application that I have ever done. I have not searched the NCH website fully, but I expect it does not warn the customer of the performance they should expect for various hardware configurations.