Now, after reading Fossie's guide, it layed down the way to get DVBViewer working correctly, however there have been some variations for myself. I figure that other people will probably have different variations depending on things such as OS and hardware etc.

I thought it would be a good idea for people to write a short description of what they've had to do to get their DVB-T/S setups working, so that others may try some of the steps to help theirs get going as well.

Heres a general idea:

Tuner Card: Hauppauge HVR 3000
Video Card: ATI HD3870 (Supports H.264)
OS: Vista x64

How I got it working:
Followed Fossie's guide for DVBViewer. After installing Cyberlink DVD 7, encountered a problem with DVBViewer reporting an error message: "Cannot load Source Filter. Error: 0x80004003. Invalid Pointer".
Resolved by downloading Monogram AAC codec (single file with file extension .ax) and copied into the C:\Program Files\DVBViewer\Filters folder. Ran Register_DVBSource.exe file and resolved the issue.

Non computer related issues:
The aerial on my roof was of poor condition. As I have a clear line of sight, I purchased an indoor UHF antenna. I can successfully receive DVB-T through this. Some channels have intermitent reception. May need amplifier.