It turns out that by default in Windows 7 there is no email client, as it was in XP OutLook Express (somehow it was called so).
The demolition of The Bat and the installation of Windows Live Mail improved the situation a bit.
But as always ... It's Windows !!!
The charset = Windows-1251 encoding does not perceive its own (!!!) in the code:
<a href="mailto:zlaya@vbudke.tut?subject=письмо%20бла-бла-бла%20с%20сайта&Body=Здравствуйте.%0D%0AХочу%20заказать%20у%20Вас%20тыры-пыры%20трали-вали%20%22Наименование%22.%20В%20количестве%20(%20)шт.%20Мои%20контакты:" target="_self">
Anyway. The affair has moved from the dead center ...
I apologize for this application (a href), but the client wants free (or rather can not afford paid) hosting.
PS How is it all the "easier" to become with the new Windows;)