access denied when mapping c$ from another computer

I am sure this is very common problem, but somehow I cannot google the solution quickly enough, so I ask here 🙂
I have two Windows 10 PCs. From PC1 I can do net use \pc2\c$, authenticate as administrator and it is a success. From PC2 I cannot do it though and I get access denied – system error 5. Local administrator account is active and I tried runas to see if I type the proper password. I also created another user and added it to administrators group, but can’t map the drive using this account either. In secpol.msc “access this computer from network” administrators is listed.
I can however map a non admin share which I have created on some folder there. So what else can it be?