Did you download the latest version from Trendnet's web site, or did you use an older version from a CD? (whichever you did, try the other and see if it helps)
But I'm pretty sure you will find that Blue Iris is better.
You cpu is under powered but there are several things you could do.
1) Lower frame rates
2)Record direct to disc under the record tab
3) Lower the live view frames per second, this is in the general options under the camera tab. This will allow you to record at say 12fps but live view at 5.
Just to clarify, the video quality is not changed with any of these suggestions. The first just merely lowers the frame rate while the second two have zero impact on the actual recording quality other than lowering the cpu. (direct to disk will require that you use the cameras time a date stamp not blue iris overlays.)
Yes you will.
If your are using direct to disc remember to check you i-frames...This is from the help file
"Direct-To-Disc
Advanced users may wish to experiment with the Direct-To-Disc feature. Instead of recompressing the video for recording, an attempt is made to save the exact stream as received from the camera. This may not be used with the Windows Media container format, and only H.264 streams are appropriate for the MP4 file format at this time.
Where this technology will be invaluable is for the recording of HD and larger frame video, as recompressing these formats is highly CPU-intensive. The down-side to using direct-to-disc is that you will not be able to add graphic and time overlays such as the time-stamp. You will need to rely upon the camera to add these itself. Also, recording must begin at the arrival of a key-frame (complete image). If your camera sends these only infrequently, you may miss the beginning of some motion-activated recordings unless you also use the pre-trigger video buffer."
You are most likely using the trendnet cameras that are rebranded hikvisions. You may be able to use hikvisions ivms software with it. It is supposed to be pretty light as it uses the cameras on board motion detection.
What error are you getting in the trendnet software? What CPU are you using in this system?