How can i resize a movie in original size

Anyone knows how i can resize a movie.

I have a film in two parts. 1,30 h each and i want to make the film in original size (about 3 hours).

There any program to do that and how?

Assuming it’s AVI format then use VirtualDub to merge the 2 parts.

Open part 1, append part 2. Set video compression to Direct Stream Copy.
Resave as new file name.

Resize?

From what you wrote, you want to put both parts togehter, appending part 2 onto 1, not resize. Resizing would be to edit the resolution.