Sharing problems on Network

I have just linked three computers to each other and to the Internet with a
router.

Two sharing problems have arisen.

The first concerns the 'office' computer. There is a database. The main
files are in one folder, and special files are in various subfolders. It was
convenient to do it like this. But now the database cannot access files in
sub-folders unless I specifically label that drive as 'shared'. Which is a
pain, because it is a virtual encrypted drive which 'loses' it shared-ness
when it is un-mounted.

One of my computers is a laptop, and is not always plugged in to the
network. Mostly it takes a re-boot to get it to 'see' the network, although
it can go to the Internet immediately. Is this normal?

But even then it does not always work. I can usually 'see' the laptop from
the 'office' computer, but not always the other way round. Is there another
way to force it to see the network?

Also if I try to install programs from my 'office' hard drive via the
network I get an error message. I have to copy the file on the laptop first
and install from there. Is this normal?

Terry