I tried to update boost from 1.60 to 1.61 using these commands:

vcpkg remove --purge boost:x86-windows 
vcpkg install boost:x86-windows

but the installation failed because of linking errors. The old build directories (1.60) were still there and they probably contained the old files. After removing these directories (buildtrees\boost\x86-windows-rel and buildtrees\boost\x86-windows-dbg) the installation went fine.

Should these directories be removed by the vcpkg remove command?
Is it ok to remove everything in buildtrees\* after installing a package?