I hope this helps you!

For Virtual Villagers 1: A New Home:

Yes, the savegame files can be backed up and/or copied to another computer that's running the same version of the game.

The procedure for backing up the files is as follows:

NOTE: This procedure assumes that you are familiar with creating folders and copying files on your computer. If you are uncomfortable with such tasks, you should seek assistance from an experienced person in order to avoid the possibility of irreparable damage to your game or your computer files.
Pause each of the games in active player slots to prevent the passage of time in the game.
Quit the game
Open the folder that contains the savegame files. The savegame files for Virtual Villagers: A New Home for Windows can be found in C:\Program Files\Virtual Villagers. The files are named Isola*.ldw, where * is a number corresponding to the player slot. There is also a backup savegame file for each game slot, which is numbered 21-25.
Select all of the savegame files in that folder. Do not attempt to open the actual savegame files to prevent the possibility of corrupting them.
Copy the files to another folder of your choosing.

If you want to use the savegame files on another computer that's running Virtual Villagers: A New Home for Windows, you should copy the files to the appropriate location on the new computer.

For Virtual Families 2: Our Dream House:

NOTE: This procedure assumes that you are familiar with creating folders and copying files on your computer. If you are uncomfortable with such tasks, you should seek assistance from an experienced person in order to avoid the possibility of irreparable damage to your game or your computer files.

1) Pause each of the games in active player slots to prevent the passage of time in the game.
2) Quit the game
3) Open the folder that contains the savegame files. The savegame files for Virtual Families 2: Our Dream House for Windows can be found in \My Documents\LDW\Virtual Families 2: Our Dream House. The files are named Virtual Families 2*.ldw, where * is a number corresponding to the player slot. There is also a backup savegame file for each game slot, which are named Virtual Families 221.ldw through Virtual Families 225.ldw.
4) Select all of the savegame files in that folder. Do not attempt to open the actual savegame files to prevent the possibility of corrupting them.
5) Copy the files to another folder of your choosing.

If you later want to restore those files to your game, navigate to the folder where you stored them, select them all and copy them back into \My Documents\LDW\Virtual Families 2: Our Dream House. Note that this will replace the files that are currently being used by the game with the ones you are restoring. If you don't want to overwrite the existing files that the game is using, you should move them elsewhere or back them up prior to restoring the files that you copied earlier.