Solutions for Playing the New on the Archaic

[kanband]

Based on the limited time I've had to look around on this forum and the hours I've spent Googling, you might find this question a bit odd. Most of the time, people ask how to convert videos without any quality loss. I want to ask the exact opposite.

I currently have in my possession a 1080p MKV file that I wish to be able to play on my computer. The big problem: My computer is old. Very old. Besides looking for a different recording or upgrading the computer (Not much in the $$ department on my end of the line), are there any solutions for intentionally reducing the resolution of the video without busting my wallet? In other words, what can I do to increase the performance of playback with complete disregard to quality? Audio is fine. The video just plays in slow motion and can't keep up. Converting the file to a different format wouldn't be bad, but from what little I've heard about re-encoding, I probably don't have the PC for it.

General Compy Specs:
1.80 GHZ processor
256 MB RAM
Old Geforce 4 MX 420 Video Card
8 GB of free HD space not including external hard drives (No USB 2.0 support though, so very slow if I use them)
Windows XP SP2

[zoobie]

reduce the resolution and bitrate to something it can handle

[Starman*]

Decoding the mkv file is what uses most of the cpu power, like 100%. Large video and high compression means lots of maths. Putting it up on the screen is less of a problem. Trying to display it at reduced res probably would not help because you still have to decode the mkv. You could recode the video at a different size and in a more convenient format but given your pc power it will take a very long time. If you run it overnight and the next day it may be done. If you choose this option I suggest you make a trial run with a short clip selected to ensure the audio sync and everything else is OK before embarking on the odyssey.