Hi all, Incase this helps anyone, but when I was inserting 4GB of memory into my laptop it had a issue with the ACER BIOS when it was telling the onboard nvidia graphics card to use a memory location that was fine with 2GB but with 4GB, that was where the system memory was and I was getting BAR 15: address space collision on of bridge BAR 1: no parent found for of device errors, which it did come down to the nvidia memory request had to be moved to another place, and also to block any requests to that place for other devices (they was able to reassign to a smaller block of memory some where else). I just had to edit the /usr/src/linux/arch/x86/pci/i386.c file and place if ((r->start >= 0xc0000000) && (r->end <= 0xcfffffff)) { dev_info(&dev->dev, " not allocating resource 0xc - 0xcf %pR\n", r); /* stop any resources gaining the 0xc0000000 - 0xcfffffff region, the linux kernel will re-place them. */ r->flags = 0; } /* where the nvidia is going and replace in the above region */ if ((r->start == 0xb0000000) && (r->end == 0xbfffffff)) { r->start = 0xc0000000; r->end = 0xcfffffff; } just after the r = &dev->resource[idx]; in the static void __init pcibios_allocate_bus_resources(struct list_head *bus_list) function.. Thought that I would post here, just encase it helps anyone else really. Ian More information here.. http://www.codingfriends.com/index.php/2010/01/07/bar-15-bar-1-no-parent-nvidia-graphics-card-does-not-work/
In your system expanded memory available only 2 GB and you are using for 4 GB at that time tour processor not support it.I am suggesting you once check user manual of your system,and scan your system with anti-virus software might be possible due to virus this type of error occurs .
since with a kernel code update to correct the ACER BIOS problems, I am now able to view the 4GB of memory, so really do not think it is due to a virus problem, and also referencing the manual the manual says that the laptop can support 4GB of memory. HTH.
