This was on a fresh install of 2.7.0-1 with no previous version ever having been installed. I'm not sure if the KWallet setup window came up during install or later once I was setting things up. I discovered it hidden under a few other windows.

Not understanding what I was doing, I chose not to setup KWallet and also chose to *not* have Last.fm passwords stored in clear text. Now every time I relaunch Amarok I have to re-enter my Last.fm username and password.

I'd like to go ahead and set up KWallet, but I have no idea how to get back to the KWallet setup. I've tried uninstalling and reinstalling, but the setup window has not returned and I can't find anyway from within Amarok to get to it. Is there anyway to relaunch the KWallet setup? Short of that, is there anyway to tell Amarok to go ahead and store the Last.fm password in clear text?

Can you check to see if an application called "System Settings" was installed alongside Amarok?
I'm not sure if it is included in the Windows distribution.

Yes, System Settings is installed. I searched around inside there, but I'm not seeing anything about kwallet.

Try having a look in Account Details > KDE Wallet in System Settings.
In particular "Enable the KDE Wallet subsystem" should be checked. If no wallet is available to select, you should create one and then make sure that wallet is selected as the default wallet.

There are only two items under Account Details, Paths and Social Desktop.

Unfortunate, it seems that the necessary KWallet components weren't included.
Please perform a search for "kwallet" including hidden directories, at C:\Users\<Username>\.

Aha! Thank you. I found a kwalletrc file. I just changed Enabled and FirstUse to true, started up Amarok, reentered my Last.fm password in the configure plugins dialog, and the setup for KWallet reappeared.

Awesome. Ideally the KWallet configuration components would be included, considering that System Settings itself was included.