Muslims are enjoined to believe in all the Holy Books then why is the Bible banned in some Muslim countries?

Banning the Bible by some is not a refection on the clear worded injunctions of God. However to confuse the Bible in its present state to the belief in the Reveled message of the Bible to Jesus is to ignore the other related verses of the the same Quran you are using as a premise to your question. The Quran also tells us that the earlier Revelations were not different then the Quranic message. So now if we find a discrepancy between the present day Bible and the Quran we will have to choose one or the other through verification. The embedded checksums of the Quran enable us to determine which of the two versions of the message is intact. Any objective researcher will arrive at the correct conclusion :)