BSOD at different times

Hi
I recently "repaired" my laptop by replacing the hard drive. Originally I was told that its the motherboard that was faulty and not the hard drive, but after replacing the hard drive, it seemed to be working OK.

However recently, at random times my laptop has been experiencing the BSOD.
I have Windows 7 Ultimate 32 bit and all the system specifications has been attached with this post.

At the moment, I solved the issue by using system restore to restore the machine to an an earlier date and at the moment I haven't experienced any BSOD.

I installed BlueScreenViewer to read the minidump and it said the the problem driver that caused the crash was athr.sys.

Any help would be appreciated
thanks.

System Model - HP Pavilion dv7 Notebook PC
System Type - X86-based PC
Processor - AMD Athlon(tm) X2 Dual-Core QL-64, 2100 Mhz, 2 Core(s), 2 ----------------------Logical Processor(s)
BIOS Version/Date - Hewlett-Packard F.22, 09/09/2008

Ok i will give this a go.
Thanks

Ok I updated the driver and it worked for a day or so, however yesterday, I got another blue screen error and since then, the machine has failed to boot up.
The error message that comes up is "No bootable device - insert boot disk and press any key" --
I was wondering, would reinstalling windows operating system fix this problem.
Thanks

Ok i will reinstall and get back to you.
Thanks