Where is the save game file? I've just closed the game half an hour ago and now when I open it my tribe is gone and I have no other option other than to make a new tribe! help please. it's VV5 and I'm on Windows 7 x64

Did anything unusual happen, such as a crash or hang? That might have corrupted the savegame file(s) for your game. VV5 automatically creates a backup file for each of your tribes, and the following procedure will help you recover your tribe(s) if the backup files are not damaged, as well.

The following procedure explains how to recover your game from the backup file when a tribe is accidentally deleted, but it will work in your situation, as well.

NOTE: This procedure assumes that you are familiar with manipulating 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.

1. Determine which tribe slot was deleted: the tribe at the top is in slot 1, and the tribe at the bottom of the list is in slot 5.
2. Open My Documents, then open the folder named LDW
3. Look for and open the Virtual Villagers folder (the actual name may vary, depending upon where you purchased the game). Do not attempt to open the savegame files, to prevent the possibility of corrupting any of them. The savegame files in that folder are named Virtual Villagers - New Believers1.ldw through Virtual Villagers - New Believers5.ldw, and correspond to each of the tribe slots. The backup savegame files are named Virtual Villagers - New Believers21.ldw through Virtual Villagers - New Believers25.ldw, also corresponding to each of the tribe slots.
4. Verify that the savegame file for the deleted tribe is no longer present (e.g. if the tribe in the 3rd slot had been deleted, there should be no file named Virtual Villagers - New Believers3.ldw).
5. Rename the backup file to make it the primary savegame file (in this example for the tribe in the 3rd slot, you would rename Virtual Villagers - New Believers23.ldw to Virtual Villagers - New Believers3.ldw).
6. Launch Virtual Villagers to verify that the tribe has been restored. The game may not be as current as the one that was deleted, depending upon how recently the backup file was updated, but you won't lose all progress on the deleted tribe.

I managed to get it to work, I only have one tribe and there were:

Virtual Villagers - New Believers0.ldw
Virtual Villagers - New Believers1.ldw
Virtual Villagers - New Believers21.ldw

The 0 and 1 were only 1 kb in size while the 21 was 90kb something, so I deleted 1 and renamed the 21 to 1 and it worked. Thanks!

It looks like something 'bad' happened to those files. It might be a good idea to back them up occasionally, just in case something like that happens again.

Yeah I've backed them up. Thanks. Any idea why it happened in the first place? I hadn't even restarted the PC when it happened.

There are any number of possibilities, and it's rarely possible to determine the reason without actually seeing what happened when the game was shut down and started again. The usual causes are computer crashes, power failures, and malware, but there is a lot going on behind the scenes in a typical personal computer, and bad things happen sometimes.