I recommend reading this topic.
Try the instructions there to try the DEMOS.
Demos for non-english versions do not require the setup (they are just a zipped folder), so you can check if they just work.
If any of the demos work we can provide further help.
After that...
Well, there is no easy way to tell you this, but I guess I will go straight:
Deadlock might never run well on Windows 10 64 bit without using a virtual machine.
Have a look at the topic that Tggtt suggested, but in all honesty, you'll have to jump through a lot of hurdles to get it to work if you can. You are probably better off just purchasing the GOG version, as it does work on Windows 10 64-bit out of the box for me, although I haven't played it to any great length and there is some sound breakup, but it does seem to work. GOG does occasionally put it on sale for US$2.99 if you don't want to pay full price.
Tarth cooks make best strudel, barbecue, bean dip, fish, cat food, smelt, piston rings, tofu and cam shafts...