HMV rolled out its Windows-based digital song download service this week, going head to head with high street rival Virgin.

But is the service easy for the ordinary punter to understand? Have HMV and Microsoft banished the compatibility issues that have dogged the market to date? And have they laid the fears of digital activists about locked music to rest?

Microsoft was alert to these concerns when it branded its music technology "Plays For Sure™". So judge for yourself from this explanation, produced by HMV itself.

Will HMV music Play For Sure on an iPod?

It surely won't, we're assured:

"Due to some software and file incompatibility, Apple iPods cannot be used with the HMV Digital service."

And what's the assurance that music you can play music you've downloaded if you choose the HMV Unlimited option, but your subscription lapses?

100 per cent that it won't be playable at all:

"Please note that anything downloaded via HMV Unlimited is a 'conditional' download, and is effectively rented. It will only be accessible whilst your subscription is active."

But doesn't everyone use MP3? Am I sure I can convert the files to MP3?

You surely can't:

"There is no facility in the player to these files using an MP3 encoder."

How sure are we that the music will play on our new PC? Why, as it happens, that's as easy as ... a support call to Bangalore:

"Please contact the Customer Service department. Just use the 'Contact Us' button and we will deactivate your computer [our emphasis].

Deactivate? That sounds drastic. But heck, you've probably already thrown it out of the window already - and this way it will take up less space.

'This digital stuff is great!', you're already thinking.

But don't these machines go wrong sometimes? How sure are we that our portable music players will play the music we've bought or rented?

Why that's easier than ever. In the old days, you'd have to remove the physical media from the packaging, put it in the player, and press start. Now in the digital era, it's even simpler!

"Please check your device is compatible with the HMV Digital service."

we're advised.

Next:

"Check that you have connected the device correctly to your USB port on your computer."

Is that all? No, wait.

"Try checking you have the relevant 'firmware' upgrades from your device manufacturer". That's 'firmware' - and you surely you know what 'firmware' you have? If that fails, then, "There may be some restrictions on the music you are trying to transfer due to the DRM (Digital Rights Management)."

The what? No worries, because:

"The details of this can be checked by right-clicking the track in 'My Library' and selecting 'Properties'. From here, clicked on the License Tab."

So you see, it's as easy as 1-2-3-4-5-6-7! It's so simple you can even slip it into a telephone conversation with an elderly relative - and they probably won't even notice. No configuration or lengthy explanations are necessary.

Worried you might forget these few simple guidelines? Again, don't worry - because HMV has conveniently provided them for you as a white-on-black JPEG image in a single point font size. Which takes less space. But as we said, you don't need to remember much.

Roll over Roger Daltry, the digital revolution has begun! ®

Bootnote: Market research company BigChampagne reports that illegal P2P file swapping has risen 41 per cent in the last year, from an average of 6.8 million simultaneous users to 9.6 million in August. Is it any wonder?