I have W7 installed on this laptop, but at the start of the repair attempt I did not have a W7 OS disk, so I used a Vista installation disc to get to the command line. Do you have windows Seven? Are you accessing the RE (repair your computer) from a seven OS disk.What has Vista to do with this? I'm now trying the same test using Memtest just in case. I also ran a windows memory test and it passed. I can get to the command prompt, notepad and ChkDsk options if that's any help. I've since noticed on the laptop CPU sticker (AMD Turion X2) the number '64' so I made a 64 bit repair disk (Advent version) but got much the same results which I've included below. I'd already tried repairing the laptop using a win7 repair disk I made from another laptop, a 32 bit Advent laptop. The startup repair detected win 7 OS, but the laptop originally ran Vista so I'm guessing the laptop is a few years old now. The results I've posted were from a Vista installation 32 bit disk.

Re: Windows won't boot after running Avast boot time scan. The problem details from the failed startup repair read as follows. Windows cannot run disk checking on this volume because it is write protected. Tried chkdsk /r again - this is what I got. Next I ran diskpart and cleared the write protection on C drive Using the command prompt I have tried chkdsk /r but it says the disc is write protected. Recovery options using the windows installation disk gave me an error I was using a version of recovery tools that was not compatible with my version of Windows. Problem details from the failed startup repair - OsVersionMismatch. After running a Avast boot time scan on a Aspire 7530 running Windows 7, the laptop is stuck in a startup repair loop which cant be fixed.

Avast scan on boot