l have windows 7 installed on my laptop but now my camera does not work anymore. I don’t know how to activate it!
It's pretty much covered by the comments the only thing I can add is go to, Start/Control Panel/Device Manager if the camera is listed then double click on it a window will open click on General this will tell you if it is working as it should, you can click on Driver then Update Driver how ever if it states that this cannot start in General Update may fail then you will have to do what the others have suggested.
Check Device Manager to see if the camera is listed. It should be in the Sound, video, and game controllers section. You should see an item for Acer OrbiCam. Look at the Details tab on the properties page of the device. Select the property "Manufacturer". It will most likely show "Logitech", "Bison", or "Suyin". Go to this Acer support page and select the Windows Vista driver that matches the manufacturer for the Orbicam (if it is the Bison driver, try the one that says "WHQL" first). Download and install this driver then check to see if the camera is working.
You are downloading the Vista driver since they don't have Windows 7-specific drivers for this machine and the driver model did not change between Vista and 7, so they should be compatible.
is there any windows 7 compatible driver or Acer 5100, the web just gives the vista one
Acer Aspire 5100 Webcam Driver
download the driver for vista and run it in windows with vista compatibility mode
1. Right click on the driver setup file.
2. Go to properties and Click on Compatibility mode.
3. Place a check mark the box in the box “Run this program in compatibility mode for” and from the drop down menu choose Windows Vista SP1.
4. Place a check mark on "Run as an Administrator" under privileges level and click on Apply and then Ok.