The usual problem in Windows 7 relates to the SPLDR service/driver - I haven't yet worked out whether there's a similar service/driver in Win8 (SPLDR doesn't exist)
Let's see if Norton have been stupid....
Open an Elevated Command Prompt window, and run the following commands
REG QUERY HKLM\SYSTEM\CurrentControlSet\services\spldr /S
REG QUERY HKLM\SYSTEM\CurrentControlSet\Enum\Root\LEGACY_SPLDR /S
REG QUERY HKLM\SYSTEM\CurrentControlSet\Enum\Root\Legacy_SLSVC
REG QUERY HKLM\SYSTEM\CurrentControlSet\Enum\Root\Legacy_SPPSVC
REG QUERY HKLM\SYSTEM\CurrentControlSet\services\SPPSVC /S
post the results.
Here are some instructions to make life easier
1) in Start, type 'Command' - a Command Prompt icon will appear, right-click on it and select Run as Administrator. Accept the UAC prompt.
2) To run the commands easier, highlight the block of commands, and right-click on the highlight – select Copy. In the CP Window, click on the black/white icon at top left – select Paste. The commands will run but may not complete the last command, so hit the Enter Key once.
3) To copy the results... click on the Black/White icon in the top left, and select Edit... 'Select All', and hit the Enter key - then use Ctrl+V or r-click+Paste to paste it into your response.