Windows 7: General Crash on x64 programs

Hi all,
I am a newbie in this forum, i just discovered it yesterday and I found it great!

Actually I was looking for some help when I discovered it xD

Some days ago I saw some notices and updates available. One of them told me that my antevirus software was deactivated, but it was actually working and telling me that my system was protected. This was the beggining of my disgrace.

Another of those updates was something about the scheduling of Disk Error Check or something like that. I decided to install it and reboot my pc to have it running. However, my pc didnt reboot correctly, it just stopped loading. Then I decided to reboot in safe mode, but it didn't load neither. After two or three hours it did start and applied the Disk Error Checking, finding no errors.

Since then, and everytime I start my computer, I am experiencing some other problems. First of all, the most evident, is an error message when loading my desktop icons, saying something about UAC and that sidebar.exe wont load. I cannot touch it from screen properties. And I can't run many programs in Program Files (x64) folder. Some of those are Windows Games, WordPad, Ccleaner or Xammp.

Does anyone have any ideas why is this happening?

Thank you so much. I'm sorry for such a long post and for my English.




P.S.: Checking the last updates I installed, I found that many of the "for x64 based Windows 7 systems" ones have "errors" as state

Welcome
In this order:
Make a full anti virus scan
Download and run a full scan with malwarebytes.
If no problems are found, go back a few days before the first problem and do a system restore
System Restore

Thanks a lot for your answer.

I'm on it. I hope I won't need to do a system restore... I've made a lot of changes in my pc lately!!

I'll tell you how it goes.

Neither Avast! nor MalwareBytes found anything... I think I will have to restore...

If you have a Seven DVD we can try a repair.

Yes, I have it! Can you explain me how to do it? I did a DVD boot, but it was trying to install Windows 7 again.

Is that whaty I have to do? If so, do I have to save my files before starting the process?

Thanks a lot for your time!!

In theory you are not suppose to lose your stuff using this process. It it were my computer, I would back up anything important. Things can and do go wrong.
Repair Install

If it were mine, I would try a system restore first.

I'll try restoring tomorrow. It seems to be less "agressive".

Is there a log or something similar to know exactly when things began to go wrong?

Maybe a way to know when I installed a certain update, or so.

Thanks again!

Just so you know
A restore brings you back to the way you were the day you took the computer home. No updates, documents, pics, SP etc
A restore goes back only a few days. Its up to you though
Back up your stuff, either way; SR is not suppose to need it, thought
You can go to search type event viewer. In the left hand panel go to administrative. In the right panel, by time, you will see what went wront.

Lets see. I have just done a start repair and... nothing happened. It is just the way it was before.

However, I have found out that the "many" updates not installed properly are actually 2, that retried almost everyday.

A security update for IE on x64 windows based systems and the "service pack 1 for x64 windows based systems". All the other updates that once failed could be properly installed in the following days.

Dunno if this helps. For the moment I'm going two weeks back in time.