Microsoft will update its security tools to detect and remove part of the copy protection tools installed on PCs when some music CDs are played. The Redmond software maker has determined that the “rootkit” piece of the XCP software on some Sony BMG Music Entertainment CDs can pose a security risk to Windows PCs, according to a posting Saturday to a Microsoft corporate Web log. The Sony BMG software installs itself deeply inside a hard drive when a CD is played on a PC. The technology uses rootkit techniques to hide itself. Experts blasted the cloaking mechanism, saying it could be abused by virus writers. The first remote-control Trojan horses that take advantage of the veil provided by Sony BMG have surfaced.