Windows XP will not connect/talk to Windows 10 and vise versa, not that i have found. the same was true of Win8 it was impossible without some nonstandard magic, if it was possible at all.
1) make sure all PC's are on the same IP range and subnet and gateway and DNS. externally pointed DNS can sometimes cause issues with internal resolution even though that seems silly, i see it everyday.
2) make sure they are on the same Workgroup
3) if you are on a homegroup then your WinXP machine is toast, not usable.... but make sure the Win7 and 10 machines are put on the same homegroup.
4) Microsoft killed the VERY basic networking protocals in Windows 10 making it even worse than Windows 8 was. i fight my Win10 machine even seeing my Synology NAS let alone accessing it and other computers, on a daily basis and i can go up to SMB 3+ for my shares.
5) if you are using a microsoft account to log into windows DONT. if your home pc is just that, then forget ever using a microsoft account, it only complicates the very basic essentials of a network because you are not Bob @ Computer1 you are
bob@hotmail.com @
Computer1, which ends up making other PC's think you are some foreign entity on the network, but when you look at your user account you are not
bob@hotmail.com you are bob or if you have a longer name like mine that might be
cyberlunacy@msn.com windows turns it into cyberl and only that, so then your authentication is even more broken.
you are only
cyberlunacy@msn.com to another microsoft app or 3rd party application which recognizes those credentials.
create a local account and use that 24/7 unless you really truly need to use your microsoft account. but expect networking issues when you do.