MEGA crashing when creating likelihood tree, any ideas?

3rd year forensic science student here, taking on a research project which is extremely important to my project supervisor. I've got limited understanding of this specific area, (funnily enough I'm starting the module related to it this year) so please bear with me, I'm trying my best! I've been provided with five notepads filled with sequences, each notepad relating to a gene region; CYT-B, ND3, Dloop, 12S, CO1. I've been asked to collate these into an excel sheet which I've done, and to clean the notepads up a bit so their identifiers are neater so I'm left with >KY472592.1 DICEROS BICORNIS SOMALIENSIS then the sequence. I met with my supervisor and they ran me through the process of using MEGA to analyse the sequences and build a likelihood tree. I took thorough notes on each step and have followed them meticulously at home. We need bootstrap rep at 1000. Using best model for each dataset and doing each separately. Every time I try to run it it gets to a certain amount of iterations and either crashes and I have to force quit or it just self terminates the program. Sometimes it happens as quickly as 9 of 1000, sometimes as far as 115. I've ran it as administrator, I've uninstalled and reinstalled, I've asked my supervisor who basically said my computer didn't have enough memory, but it's got 24gb RAM and as far as I'm aware it should have no issues running this. It runs Starfield so... seriously? But then I don't really have a clue when it comes to computers. I just don't know what to try next. I really want to get this done. My supervisor offered to do it themself however I feel like that defeats the point of me doing this project and I'm frustrated that I can't figure it out, though I've only been trying for a day. Please any advice whatsoever is greatly welcomed and appreciated!!