If you want to rebuild the master database you can run Rebuildm.exe command prompt utility. This utility allows you to rebuild the master database to change the character set, sort order, or Unicode collation. You can also use it to fix a corrupted master database. The Rebuild Master utility reinstalls the master database. When you run the Rebuildm.exe command prompt utility you can select new character set, sort order, and Unicode values and rebuild the master database with the new settings. You can find this utility in Mssql7Binn folder.