i cannot switch on the bluetooth  

Then as i don't use Bluetooth myself, I am unable to asist, I'm afraid. I would urge you when you get this matter sorted to do an image backup of your system With that it is so easy then to re instate your machine to a working position. For others to help you it would be a good idea to complete your system specs properly. Just having the OS detail is not enough. here's the perfect guide :
System Info - See Your System Specs

At a minimum, we need to know the exact model Acer you are working with. an you also provide a screen shot of what things look like in Device Manager?

According to the Acer website: Acer Support: Downloads & Support Documents - Notebook, Ultrabook / Aspire / Aspire 5742G, your laptop (Aspire 5742G not 57425G) has one of two Bluetooth modules, either one from Atheros or one from Broadcom. Which driver did you attempt to install and how did you determine which Bluetooth hardware is installed?

You should follow the instructions given by Mitchell65 above to determine your system specs and hopefully that will identify which Bluetooth hardware you have so you can download the correct driver.

Have you attempted to determine WHICH Bluetooth hardware you have installed?

Since you have tried both drivers unsuccessfully, it may be possible that the Bluetooth module in your laptop has failed. Is it still under warranty? Have you tried contacting Acer for support?

One quick way to get Bluetooth on your laptop is to simply use a Bluetooth USB dongle. These can be had for as little as $2 and work great. I have a number of them and have had zero issues. Here's some examples: Newegg.com - bluetooth dongle usb

If that mouse is Bluetooth, then yes. If the mouse has any special features such as the ability to assign different functions to different keys then the mouse will have a driver or utility that needs to be installed. However, if you don't install the utility, it will still function as a "standard" mouse.

I've used those little Bluetooth dongles on netbooks, notebooks, Android devices and desktops and have never had to manually install a device driver (using Win 7, Win 8 or Android 4.2). Just plug the dongle in, the OS downloads a driver and the thing works. The only difference I can see between a $2 dongle and a $10 dongle is construction quality, above $10 and you're paying too much.

I recently purchased 3 of these: http://dx.com/p/ultra-mini-bluetooth...0-dongle-37665. I really like them because they are so tiny that they don't protrude very much and are almost unnoticeable when plugged in.