I have 3 PC’s networked through a router. All able to access the Internet. Both PC2 and PC3 can see PC1 in Windows Explorer and files can be moved between all three. PC 1 cannot see the other two in Windows Explorer but by using Windows Search Companion and look for computers, PC 1 can see the other two and I have subsequently therefore created short cuts on the desktop of PC1 to access 2 & 3. The system has been fine for a very long time and only displayed the problem recently. The question is – Why cannot Windows Explorer see PC2 & PC3?