The Witcher: Enhanced Edition...

RU version is playable only in Russia.

BUMP

(RU) is usually a region lock because their games arent censored, so you might wanna try and trade it back

except in the rare case of sleeping dogs

As i can see , only Witcher 2 has region restrictions (use a russian proxy and look at the steam page in your browser, be sure to be logged off), Witcher 1 has no such restrictions.

In case you have still doubts, Steam Russian store The Witcher 2 page states:

"Purchases made in Russia are only playable in Russia, Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Tajikistan, Turkmenistan, Uzbekistan and Ukraine"

No problem with The Witcher 1, but you can't play the second one.