Windows 7 - Windows 7 host cannot startup after Guest Additions install

hi every one.
after i installed "virtual box guest additions" on my OS(win 7 ultimate),it can't start(up).
The OS has not a restore point.
what should I do?
Cheers

Hi Saeidmscs

You have no Restore Points at all? Not even the ones that Window's makes by itself? are you sure?

Try booting into Safe Mode to check:
1) Start your PC and spam F5 until a screen asking you to select your OS appears,
2) Press F8
3) Select "Safe Mode"
4) In the Start Menu type System Restore
5) Click "Restore your Computer to an earlier point in time

Windows makes Restore Points for itself automatically every few days or when it installs updates, so unless you have Restore turned off, then its unlikely you have NO restore points. Post back with your findings

yes,I have turned it off(but will never do this mistake!)
Even in Safe mode,the OS doesn't start up!
just a black screen.nothing more.

Oh Dear, you may have to reinstall Windows. Don't do that just yet though, I will ask some of our Guru's who are more experienced with this sort of thing to take a look at your post. (not really my speciality)

Thanks my friend.
I wait for it

the first time i installed the guest additions into Windows 7 instead of the ubuntu guest i was running and had big troubles! you didnt do that did you?

The first thing to try, assuming that you have a Windows 7 bootable media, is a start-up repair.
Boot from the DVD/Stick and select Repair my Computer option follow instructions.
Do this up-to three times, (even when it appears to work the first time), or until it states that no problems exist.

Post back the results

If you don't have any install media or other recovery disc, you can go here to download a burnable recovery disc ISO: Windows 7 Recovery Disc

After downloading, you can burn it to a CD or DVD using ImgBurn.

I am going to do above instructions and will be back soon.

Startup Repair