After installing Windows 8 in a dual kind of boot with Windows 7 but you find the menu for graphical boot is missing, there are steps you can follow to reinstate it.
Create a recovery drive for Windows 8 first. After recovering the drive do a PC restart while opening the BIOS setting to make sure the PC supports a USB boot.
Boot the system into Windows 7 and press Windows plus R for Run dialog. Type msconfig followed by Enter to have the System Configuration opened.
Do switch to the Boot tab and choose Windows 7 and select the setting as default.
Connect the former Windows 8 created recovery drive followed by a PC restart. Do the needed changes within BIOS for USB booting to start.
Choose keyboard layout and choose Troubleshoot and choose Advance options. Click the Command Prompt finally to have it opened.
Within the Command Prompt, write rebuildbcd/bootrec and tap Enter. Wait for a while and type ‘All’ followed by Enter after seeing a query to add installation for boot list.
Close the opened Command Prompt and tap the option for turning off the PC.
The recovery drive for Windows 8 can be removed as you turn the PC on and do a Windows 7 boot. Open Run dialog and write msconfig followed by Enter.
Finally change into Boot tab and choose the entry for Windows 8 and set as default. Tap Apply and restart PC and the Windows 8 menu option for graphical boot will be visible.