Windows 7: Error 0x0000428 - winload.exe

Yesterday when I trying to change the bootscreen with new Bootscreen of Windows 8 Build 7989 (I get it from windows 8 italia), I use Windows 7 Boot Updater application. When it processing... (I forget what's that processed when it turned off). Suddenly the power supply of my netbook went off. It's caused by my home electricity.

Then I turned on my computer, when i select to boot from windows 7. Then appeared text like this :

Due to some recent hardware change..... (It's so long text, I hate it)

File:\Windows\System32\winload.exe

Status:0xc0000428

Info:Windows cant verify the digital signature for this file.



It says, I must press the F8, when I press F8, it appeared again...

My netbook is dual-boot, Windows 7 Ultimate and Windows 8 Build 7955. I look some website, tells me to repair it with EasyBCD. I tried it using Windows 8, but when the installer of EasyBCD and install dotnetfx.exe (Is it Microsoft .NET Framework 2.0?) it's cancelled and roll back automatically. It looks like the dotnetfx doesn't compatible with Windows 8 Build 7955.

Is there any other way to fix it? Can you give me a detailed solution?

Thanks. (P.S. : I don't have the DVD of Windows 7 because I lost it sorry for my bad english)

Windows 8 is not official yet.

But what you can do is download BCD Editor - Windows 7 / Vista.
It has a "Dual-boot Repair" utility.
Start it and click on "Automatic Repair". Confirm.
This will repair the Windows 7 boot environment files:
bootmgr - Windows boot manager, the BCD and boot records(MBR and PBR).
and make Windows 7 boot by default.

If the entry for Windows 8 is missing when in booted in Windows 7 run
Visual BCD Editor, click on pop-up menu "Create missing Windows loaders"
and confirm. This will scan your system and add an loader entry for Windows 8
or any other installed Windows 7/Vista/XP or VHD.