The shared disk of my Version 7 notebook is visible in my two PC's with XP Pro and XP Home, but in the PC with Win98SE I get a request for a password and it does not work no matter what I type in.

Try disabling the Password Protected Sharing requirement, this would be in the Network settings in the Control Panel. http://windows.microsoft.com/en-US/windows7/Networking-home-computers-running-different-versions-of-Windows

Please understand that Windows 98 is not supported anymore. Therefore we strongly recommend that you upgrade the Windows 98 system to a later version. However, in order to answer your questions, I would like to involve the following article. File and Printer Sharing in Windows Vista This article is applied for Windows 7. To make the file sharing work, you need to change the NTLM level to version 1. Please refer the article for detail information.Please remember to click Mark as Answer on the post that helps you, and to click Unmark as Answer if a marked post does not actually answer your question. This can be beneficial to other community members reading the thread.

What puzzles is the appearance of window requesting just a password, but no logon/user name. Password of what? If I knew that, I would not mind typing it in! I have the same user name on all machines. As stated, Win98SE shared disks are fully visible in the Windows 7 machine. I understand Win98(SE) is not supported any longer, but since disk sharing between Win98 and XP works in both direction, I can't see why I shouldn't with Win7 - in other words, why releasing a new OS prevents something that previously worked from working?