You can play this game only with WinXP SP3 😳

Please, read the f...g guide!!!

You are clearly an a-hole and I shall have to turn you into a freakish monster as there is NO such thing as XP SP3!

As for the Toolkit, I don't know how to use it and besides, Lemmings Revolution isn't THAT old.

Hear me, Oh Powers of Sylvarant and Tethe'alla;
turn now El nostalgico into an Exbelua!

Don't have the full game but I do have the demo and the sound works fine over here.

You could try the standard stuff.

game patch
reduce sound acceleration
check read-only
compatibility mode on/off
clean out ears
etc..

I already said that I have the latest patch. I tried compatibility mode and it didn't help.

Is sound working under windows alone? Do you have volume/speakers muted?

Haha yes there is no such a thing like XP SP3. 😏

Yes latest Service Pack for Windows XP is SP2.

Yes, sound in Windows is working.