Question about Acer Aspire 5 (A517)

In principle, you can install/upgrade a hard disk on this model. I have also done this successfully with this HD (https://www.digitec.ch/de/s1/product/seagate-barracuda-1tb-25-notebook-festplatte-5961124) and this laptop.
However, you need not only the HD but also a mounting frame AND the cable to connect the HD to the motherboard. Both are not available at digitec and have to be ordered from other online shops. In addition, the entire bottom cover must be removed, NOT just the existing HD slot cover, in order to be able to plug in the cable. All in all, a lot of work, but doable if you've done it before.
Acer seems to have a policy of making later upgrades (HD or even SSD swap) impossible for the normal user. For this, the next higher laptop must be bought, with an extra hard drive installed. Actually, it's a pity, because up to now I have been very happy to buy Acer laptops, as they are very much ahead in terms of price/performance. After this experience, the picture is unfortunately somewhat different.