1) both machines need to be in the same workgroup.
2) to RDC to the old machine from the new machine or map a drive to the old machine you need to create a user account on the old machine (make it an admin account so that you don't have permission issues and you can map to $ shares.)
3) if you want to run programs on the old computer, RDC to it and run them on that machine
4) if you want to copy data from old to new:
- go to my computer on the old machine
- right click on C and then sharing
- enable sharing on that drive
- map a drive to \\oldmachinename\C$ (assuming your data is on the C drive) and then just copy the data to the new machine

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