If I were you, I'd take Oracle DBA certification over MCDBA. IMHO Oracle is a bit more "open" than MCDBA from platform standpoint and from technology support standpoint, but have a go, here: Microsoft Learning: Microsoft Certified Database Administrator (MCDBA)
I don't see any test as "hard", it's just a test... It tests your knowledge and your decision making accompanied by your experience in using/maintain/support/install/configure/administrate certain MS products. If you don't have enough experience, usually you'll bump a road block in the test.
Ps. I've gone quite long and far from MS solutions these last 5 years... I've fell in love with Linux, for now - I see Linux as the best Server
solution out there EVER. As for clients, I still recommend any Windows clients over any other client OS out there, just because of the ridiculous driver
support MS client products have...