Problem with network

I have two computers on my network. For the sake of brevity let's refer to them as PC1 & PC2.

PC1 is my main works computer and PC2 is a secondary computer I use for my ham radio operating. Like I said, both PCs are connected into a network switch. What I look under "network" I can see PC2 listed, however, I can't see PC1 for some reason. If I go to "network" on PC2 I can see PC2 listed also. Up until a few minutes ago PC1 was also showing, however, that has mysteriously disappeared.

I'm now back on PC1 and want to transfer some files over to PC2. Normally, I would just click on PC2 under network and go into the public folder and find public documents for example. However, when I go into the folder public, I'm just seeing two folders, default, and default.migrated. If I click on either of these folders I get a box, telling me I don't have permission to enter.

So I'm hoping someone can shed some light on what's happening.

Often its just netbios being slow can you connect via IP instead of name? run this scanner on both pc see if it can see it it often wakes it up note which is master browser https://www.nirsoft.net/utils/netbios_scanner.html

Thanks for the reply. I ran the scan but nothing really happened. What is it supposed to do?

All the settings on both computers are set the correct way so they should be able to see each other. It was working the other day with no problems at all, then all of a sudden it stopped working.

If I click on network on PC2 I can see both computers listed. I can click on PC1 and see all the public folders but under network on PC 1 the computer isn't showing so even if I did put some files from PC2 I wouldn't be able to access them because the computer isn't listed. Sorry, that probably sounds very confusing

When you run the scan you should see all of on the network are you saying it didn't find any?

Yes, found both computers. I thought I was getting somewhere before. On PC1 I right clicked on my documents, went into properties, then sharing, advanced sharing and checked share. I noticed that this PC appeared on the network. However, after restarting this PC it is no longer showing under network. I did the same on PC2, however, only documents appeared but I'm not able to access the folder because it tells me I don't have permission

Folders under users profile have special permission even on the pc as admin you have problems accessing other user folders. Set a share away fron there give everyone rights then set up NTFS permission on the folder.

Windows doesnt look for pcs it simple asks the master browser for a list which is why I asked you which is MB. If you turn a pc off it will drop from the list and when you turn back on it cane take over 10 mins to be found but you can access via IP instead of the name

I've just taken a screenshot. Rob is the other PC on my network. The PC I'm on now isn't showing a network.
Do I need to go into advanced sharing? I've already checked the box in advance sharing. When I do this, the two folders public and users are then visible, however they are not accessible as you can see by the screenshot

Have you set permission on the shares and NTFS if you connect as a different user and give username and password for the pc your connecting to do it work