Reader Nayana has two PCs on her home network--one running Windows XP, another running Windows 7. Curiously, the Windows 7 system won't let her access shared folders on the XP system, but it does work the other way around: she can access the Windows 7 folders from the XP machine.
Bleh. Windows networking has been a nightmare for as long as I can remember. Thankfully, Windows 7 solves a lot of the headaches--but only if all your PCs have it. If there's an XP box in the mix, problems like Nayana's are all but inevitable.
Much as I'm a fan of DIY fixes, tinkering with Windows' networking settings (especially XP's) is so confusing, frustrating, and frequently fruitless, I'm going to suggest a different (and much simpler) solution.
Yep, you guessed it: Cisco's Network Magic Essentials. Install this fantastic utility on both your PCs and in no time you'll be swapping files, sharing printers, and so on. Trust me: it's the path of least resistance.
The software costs $29.99, but there's a free 7-day trial. If your main goal is simply to migrate files and data from an old machine to a new one, that should be plenty of time.
One word of caution: for reasons I don't fully understand, Network Magic's system requirements make no mention of Windows 7. The software is compatible, but I suspect Cisco may have halted or abandoned its development--probably because of Windows 7 networking features like HomeGroup.
In any case, before you spend a lot of time trying to troubleshoot networking settings manually, give Network Magic a try.