Hi,
I was using Avast IS trial and password protection tool. But i forgot my password, so that i used avastclear to uninstall Avast IS trial and then re-installed Avast again. Right after that i got blue-screen error on my laptop. It happens once every 3,4 days. I dont know what happening to my laptop or what i should do.
I m using Asus X550LC, Win 7 64bit. Any help from avast? 
PS: Sorry for my bad English. I m not an English native speaker. 
do you have any other security programs installed…like another antivirus?
Do you get any error codes from Windows when you see the Blue Screen?
Nope…Avast IS was the only anti virus program i used.
"A problem has been detected and Windows has been shut down to prevent damage
to your computer.
The problem seems to be caused by the following file: ACPI.sys
ACPI_BIOS_ERROR
If this is the first time you’ve seen this stop error screen,
restart your computer. If this screen appears again, follow
these steps:
Check to make sure any new hardware or software is properly installed.
If this is a new installation, ask your hardware or software manufacturer
for any Windows updates you might need.
If problems continue, disable or remove any newly installed hardware
or software. Disable BIOS memory options such as caching or shadowing.
If you need to use safe mode to remove or disable components, restart
your computer, press F8 to select Advanced Startup Options, and then
select Safe Mode.
Technical Information:
*** STOP: 0x000000a5 (0x0000000000001000, 0x0000000000000000, 0x0000000000000ff0,
0x0000000000000025)
*** ACPI.sys - Address 0xfffff88000fab2d7 base at 0xfffff88000f8e000 DateStamp
0x4a5bc106"
That’s what i got when bluescreen appeared. I used BluescreenView apps to read this code.
Do you have the latest bio’s installed from the Asus website http://support.asus.com/Download.aspx?SLanguage=en&m=X550LC&p=3&s=516
It looks like a common problem, Google " ACPI_BIOS_ERROR "
http://msdn.microsoft.com/en-us/library/windows/hardware/ff560114(v=vs.85).aspx