How can I download a video from a tweet on my pc?

If third-party downloaders don't provide the quality you need or if the video is protected, the most polite and effective solution is to contact the original author to directly download video from tweet. Send a brief, friendly direct message (DM) or reply to the tweet, explaining your appreciation for the video and your need for a high-quality copy. 

Many creators are happy to share their original files for non-commercial or personal use if asked politely, especially if you plan to credit them or are a fellow creator.

By reaching out, you ensure you get the absolute best quality file (the original source) while respecting the creator's ownership and avoiding potential copyright issues associated with unauthorized downloading.

This also opens a line of communication, which can be useful if you intend to use their content publicly and need formal permission.