確認だけど、OS再インストール後もそのTCボリューム化されてるHDDを TrueCrypt.exeでmountできないんだよね？ user guide.pdfに以下の事例があるみたい。試しにhandle.exeとかunlockerを 使ってそのHDDを掴んでるプロセスがあるか確認するといいと思う。
PROBABLE: 2. NTFS TrueCrypt volumes cannot be created In addition, the following error may be reported: "The process cannot access the file because it is being used by another process." PROBABLE CAUSE: This is probably caused by an interfering application. Note that this is not a bug in TrueCrypt. The operating system reports to TrueCrypt that the device is locked for an exclusive access by an application (so TrueCrypt is not allowed to access it). POSSIBLE SOLUTION: It usually helps to disable or uninstall the interfering application, which is usually an anti-virus utility, a disk management application, etc.
