Is Humbrol Maskol any good?

I tried painting window frames with masking tape, but I can't get the result to be any better than painting it by hand.

This is mostly because I use normal masking tape instead of the thinner Tamiya tapes, I guess.

But the nearest store to my house that carries modeling masking tape is a 45 min. drive away.

But I did see Humbrol Maskol at the place I usually buy my paints.

Is this stuff any good?
And does anyone have some nice tips on using it?

After applying Maskol can you cut it along the windowframe and peel it of before painting?

I've not used the Humbrol brand, but I've used other brands of the same stuff. Yes, you can cut and peal, but sometimes it lifts. Just mask close to the edge with tape and coat over the tape when you apply the goo. Then when you go to remove the masking the tape will help you lift the masking off.
I use BMF (bare metal foil) to mask window frames and stuff like that.
Do the same as above, mask close with tape and overlap the window frame with a strip of foil. Then trim the foil with a new blade.
:p

You cannot cut Maskol after it's been applied (and obviously before it's been applied :D). I'm afraid your best option is to get Tamiya masking tape. If you don't want to drive to a shop and stock up for months, you can order from e.g. Japan. It will take more than 90 minutes though ;)