Solution to problem in that Nero would not install as it continually indicates the need for a reboot: CCleaner (v2.07.575) has an Internet Explorer setting to clear index.dat. With CC set to clean on restart, this removes Index.dat and marks the system for a reboot by setting the "PendingFileRenameOperations" Registry Key. When you try to install again, after a reboot, you get the same message. Turn off the 'Install.dat' option clears it. (-Took me 2 frustrating days to find this.... I hope that this helps others. (A search did not indicate this problem/ solution here...)
nero clean tools from there website not work for any versions you had previously installed then? v6 v7 v8 tools, even if you had v6 installed once and useing v8 use the nero v6 toll etc etc, need to sue all if you had all once installed. oh and nice find! ;-]
I had had v8 installed before (and earlier versions prior to v8), but had had to do a complete reinstall of everything from clean HD, XP up. Hence had lost old settings and, presumably, did not have delete index.dat set before. (In order to delete a corrupt Bluetooth-related system file somewhere, I could not go back to my faithful Acronis TrueImage files, which would have saved 6 days and 23 hours.) I doubt if Nero clean tools would have cleared it because as soon as CCleaner was run it would set index.dat to be deleted by reboot and hence the Nero installer would have asked for a reboot...