homegroup not work - network drive can't remember - please help

Greetings.
I'm a total newbie on homenet in Windows 7 and windows 8, so please bear with me on this.

Earlier I had a Windows 7 "main-PC", and a small (very small) PC running 24/7 with WinXP. With that my network drives worked fine from Windows 7. I could read the drive on the XP, but not the other way. That was OK.

I then got a Windows 8 pro x64 upgrade licens, so I upgraded my Windows XP to Windows 8 Pro, thinking that home-network now just run without problems. What a mistake

At first I tried to create a homegroup on my Windows 7 Ultimate x64. Some services did not run, so I checked your guide to create a home group Homegroup - Create. That was not possible as I first had to change the language in my Windows from danish to english, and after that try to find the services the guide need.

Function Discovery Provider Host and Function Discovery Resource Publication is not on my servicelist, so I don't know what to do. In settings of homegroup, I can mark the things I want to share (pics, music aso), and then save the setting. But next time I look at this page, I share nothing again. It does not start sharing anything. At the Windows 8 PC I have joined the homegroup and typed the password got from Win7-PC. It claim to be connected to the home group, but no other computer is to be seen. The same in the Win7-PC. It also claim to be connected to the same homegroup, but no other computer is to be seen. Homegroup was created witn win7, and homegroup was joined witn win8. After 2 weekends test of this I gave up.

This let me on to make an oldfashioned net-drives. That did not work, as I had same username and password for the 2 PC's. OK, I removed the password from win8 PC. Rebooted both, and then when I tried to make a network drive from windows 7 to a shared folder on the win8-PC it asked me for name and password. I typed the name, but no password, as there is none. That worked! sweet. But when I restart the Win7 PC it can't reconnect, as it can't remember the username I typed when I mapped it the first time. There is a setting called "remember my credentials", but nomatter if I mark this or not, it STILL ask for a username after a reboot, or a log off/log on.

I might be to stupid to understand your guide for setting up a homegroup, but am I also too stupid to make a mapped network drive work after a reboot?

The reboot thing is a problem as Microsoft sometime sends an update, so Windows restarts without I'm around to type the username and/or password, so the PC's must be able to share these folders without I have to do anything after they are setup.

Anybody has the patience to help me, please?

Can anybody help me to what service must be running to remember Username and password for a network-drive? After reboot, my Windows 7 can't connect to my networkdrive without I have to reenter username.
Home-group is given up, so only network-drive has interest right now.

Please, share some gold-ideas.