Is it ethical to watch recreational videos or listen to music on a portable work computer bought from a research fund? I am in my first year of a PhD in France. My adviser recently bought a laptop for me using the research funds on which the computational codes for my research work are installed. According to my adviser, I can take the laptop to my residence when I leave the lab.


  Is it ethical to listen to music, watch videos or movies I love on the work computer?


I am well aware that discussing with my team would be the ideal thing to do but I am not sure how my supervisor would take it. I cannot reach a conclusion of whether listening to music and videos helps me constructively in my research. One favorable justification I found is that listening to music helps me concentrate better, but I am not sure it is always the case. The reason is that at times some movies feel very motivational, music feels soothing but on some other occasions I find myself investing hours in them when I am supposed to complete a task. This may be purely attributed to my personality but I am unable to reach an answer.
Unless explicitly stated in the rules that they should have told you when you got the computer, you can do whatever you want that doesn't damage the machine or compromises your work. Common sense applies:


Playing a CPU intensive game at the same time you are crunching some numbers you need soon will slow your computations, so it isn't good. Playing the same game while the CPU is doing nothing else, should be OK.
Storing music or films in the hard drive is fine, but if you are running out of space for your data, they should go away.
If the university is providing some backup service, make sure you are not bloating it with gigabytes of your personal stuff. A few megabytes of configuration files of your own programs and other small things shouldn't be an issue.


One can argue that just by using it you are wearing off the battery, and that is costing your university money; but on the other hand, a new battery costs around one salary day, and if that is what it takes to keep you happier and more productive (even a tiny bit) for years, I think it is well worth it.

If you were to need the help of IT support (in my university is as good as nonexistent anyway), they may delete your personal files and programs if they think they are related to the problem, as  Todd Wilcox pointed out in the comment. If they were less understanding, you may even be told off for installing software that they don't know (mind you, it may even be research related!).