thanks unamis I will try that, but how do I do that in windows if its a icon on the desktop.
The short answer is that you either need to run the .exe directly from the windows command prompt with the extra argument, or you will need to make a .bat or .cmd file which runs the wallet with the extra argument. In any case make sure you are running it with a secondary copy of the wallet file, since it could hypothetically further corrupt the wallet and make the situation worse than it is. Back up your wallet file securely and often. This should be your number one rule for any crypto currency anyway.
I'd like to avoid turning this into a windows support thread so for some details of how to do some general things on your computer you will have to do a bit of Google. (We can't teach you to computer, this is not an appropriate venue for it.)
Now that you can read the wallet at all you should take pause and do some accounting. With the wallet file loaded and the client synced, go over your transaction history shown and determine what addresses/coins that wallet file has access to. If it is missing some of your coins, you'll want to make a separate list of addresses/coins that you know are yours but are not on your first list. Hopefully -salvagewallet will make the first list longer and the second list shorter, but the odds are probably against you. However, if anything is left on the second list you have some more work to do. You'll want to cross-check against block explorer and deposit/withdraw history on hosted-wallet services like exchanges to determine if any missing coins are missing because they are in another of your wallets, or missing because they were never sent to you at all. In the first case you'll want to find any missing wallet files and consolidate into one wallet, and in the second case you'll want to contact the service's support. (We also can't be your accountants.)
In no case has your wallet been "plundered" unless someone else has your wallet keys. Also, if this were the case, you would see the outgoing transactions in the chain and could attempt to investigate from there. However, this is even more work that you'd mostly be on your own to handle. (We certainly can't be your detectives or police!)
Best of luck. We're rooting for you. We've mostly all been there, and we know how much it sucks.