My xperia zl, running android 4.4.2 kitkat indian update using ftf file, which is rooted using towelroot apk, i had installed supersu and busybox latest version, just now only I had connect my xperia zl to pc, then in sony pc companion my xperia zl had'nt recognized as usaul because my cell is rooted, there just written xperia device, but it had given me update to cell, even it had'nt given me the update build no, just update, during the downloading process it had said that to remove the cell, as i had disconnect it from my pc, but the update is downloading now, so is it would be harmfull to my xperia zl or I should upgrade my xperia zl ?