Boot manager missing problem in dell Inspiron 1545 with windows 7

When Windows 7 does not start correctly or not at all, there are three options to restore the Operating System on your computer to fix computer issues such as infections, corruption, crashes or to clear your personal information from the computer.  Follow this how to restore, reset, or reinstall Windows 7 on your Dell computer.

https://www.dell.com/support/kbdoc/en-us/000194228/restore-factory-reset-or-reinstall-windows-7-on-your-dell-computer