USB oder Externe Platte angeschlossen,wo ein BS drauf ist.Evt. auch den Bootsektor zerschossen von der normalen HDD bzw.SSD.
Windows ist auf der SSD?
Put the Windows Vista or Windows 7 installation disc in the disc drive, and then start the computer.
Press a key when you are prompted.
Select a language, a time, a currency, a keyboard or an input method, and then click Next.
Click Repair your computer.
Click the operating system that you want to repair, and then click Next.
In the System Recovery Options dialog box, click Command Prompt.
Type Bootrec.exe, and then press ENTER.
8. Type bootrec /RebuildBcd , and press Enter.
For more information refer the link given below:
How to use the Bootrec.exe tool in the Windows Recovery Environment to troubleshoot and repair startup issues in Windows
http://support.microsoft.com/kb/927392