i need a server for my backend file access database

No you don't necessarily need a server specifically.  You just need a location that everyone has access to.

Access is a bandwidth hog, so you need a LAN connection, no wireless, no internet drives, local.

As for NAS drives, i avoid them.  Typically, they don't work for multiuser Access databases, but not all NAS drives are created equal and some can support it.

Personally, if you don't have a server, then try the NAS but dont be surprised if it doesn't work.  Then the solution would be to create a shared folder on someone's PC and share it from there. In that case, don't forget to stop frequent backups!

First, lets get some terms straight. There are two basic types of LANs; Server based and Peer to Peer. In a server based LAN you have a separate computer that functions as a domain controller. With only 3 PCs you probably have a peer to peer. This uses the Workgroup feature of Windows to allow communications between the 3 PCs.

While you can certainly use any NAS as a file server on a peer to peer LAN, it is not necessary to do so. The advantage of using a NAS is that every PC can map the NAS as a the same drive letter. But you can use any one of the PCs as your file server, you just have to use UNC coding (\\computername\sharename\foldername) to link the back end. However, a NAS would be my preferred choice (I have one for my home machine). The NAS can remain on all the time. It can be easier to backup and can be addressed from every PC on the LAN.

First, thanks for your responses.

I dont know what device i must buy (cheap but not bad). Can someone tell me what server (or nas) i must buy? thanks

Any NAS unit will be suitable. I use a QNAP device. QNAP has many models. But Western Digital also has several NAS devices. There are a lot of them. Again, you don't need a server, just a storage device that can be access by all the PCs on your LAN. This is assuming you currently have a switch that all three PCs are connected to. The NAS device would then connect to that switch.

You don't need a NAS or Server, you could just use a shared folder off of any of the existing PCs.

One of them has to be the server with backend file only, because now when person Who has backend file in his computer works with the frontend in same computer causes errors in the other computers .sorry about my english  

You honestly do NOT need a server, you do NOT need a NAS, and you do NOT need to buy any new hardware.

If your three computers are connected by a network, you can put the "Backend" - the Access database containing the tables - on any one of your three existing computers.  The backend must be in a folder that has its Permissions set so that all users have read, write, create and delete permission for files in the folder. Each of the three computers should have its own copy of the "Frontend" - the database with the Forms, Reports, Queries and code - linked to that backend.

If you are still getting errors please post the actual error message; we can translate it if needed and help you get it working.

Hello, thanks for response.

What happen is when person who has the fronted and backend (called Marc for example) opens the access, then the shared file get blocked and the other users cant works.

but if the other 2 persons works in the backend file (and Marc is not working) all works like a charm. Then Marc open the frontend for work and bloked database for the others.

I read documentation of access split databases and they say that only the server has to have the backend file (and no frontend file in it) can i makes me understand?

As others have said, you must ensure that the folder hosting your Backend has the correct permissions. All users need Read Write Create Destroy permissions on that folder, so you must be sure to enable those permissions on the folder.

Regarding splitting your database - you should have a SINGLE copy of the Backend, and that Backend should be placed in a folder that is accessible to all users, and has the correct permissions set (see above). You should reconnect your Frontend to that Backend, and then make COPIES of the Frontend, and distribute those to each user. Each Frontend would be installed locally on the users machine.

I would avoid a NAS drive, due to performance reasons. They work fine for development, but in many cases they be a real performance bottleneck.

As I said, in my original response, you don't need a NAS, but it can make things easier. I have used them on my peer to peer and on work LANs. As long as they are hard wired, they work fine.

But it is not necessary. If the database is split and the links use UNC coding (as I also mentioned in my earlier response), then the user with the back end on their PC should not be locking out other users. Each user needs their own copy of the front end.

The documentation you read is correct, but it assumes a server based network. A peer to peer network works differently.