Unzipping .spk on Windows?

[austinderrick2]

How can I unzip a .zpk file on windows? 🙁

[goldbug]

Well, which is it?

.spk (Acorn Spark archive)
or
.zpk (Z-firm)

[austinderrick2]

oops... I meant .spk as in Acorn Spark Archive.

Hope you can help me 😃