Patching the DSDT table for 8510p to reduce fan noise

Following the previous post, here are the steps that worked on my Vista SP1 x64 notebook.  Please note this is for reference only, this could damage your machine.

1. Download the Microsoft ASL Compiler v3.0.1 and install it on your notebook.
   
2. Start a command prompt using "Run as administrator" to make sure you have the correction permissions.
   
3. Create a working directory, I used C:\DsdtPatch.
   
4. Copy asl.exe from C:\Program Files (x86)\Microsoft ASL Compiler v3.0 to your working directory.
   
5. Extract your current AML data from your registry.  It is located at HKEY_LOCAL_MACHINE\HARDWARE\ACPI\DSDT\HP____\8510x\00010000.  You need to extract the binary data in the key 00000000 to the file system.  I've written a quick and dirty .Net program to do that.
   1. Unzip ExtractDsdt.exe into your working directory.
   2. run ExtractDsdt, a file 8510x.orig will be created.  Make a backup of this file.
      
6. copy 8510x.orig 8510x.aml
   
7. asl /u 8510x.aml, the file 8510x.asl will be created.
   
8. Open 8510x.asl in notebook.  Now we begin our patching.
   
9. Search for the following (note the pattern could be different for your machine).
   
   For my F.0F BIOS the original values are
   
   Name(C357, Package(0x6)
   {
       0x64,
       0x4b,
       0x3c,
       0x32,
       0x1e,
       0x0
   })
   
   I found it easiest to search for "Package(0x6)" from notepad, that should take you to the right section, check that there are 6 hex values within the braces and within the _TZ_ scope.
   
   Each value should represents the % fan speed at each temperature trip point in hex.  I changed mine to.
   
   Name(C357, Package(0x6)
   {
       0x64,
       0x4b,
       0x32,
       0x1e,
       0x14,
       0x0
   })
   
   Save your file after your changes.
   
10. Now we can compile our updated 8510x.asl back to 8510x.aml.  Execute asl 8510x.asl, I ignored the warnings, but if you get errors, go back and check your syntax.  If you get "error: expecting Symbol '('" the number in the brackets is the line number, go to that line in 8510x.asl and add a pair of bracket () to the end of the previous line, I had to repeat this a few times before it will compile.
    
    For example, change
    
    If(LEqual(Arg0, 0x0))
    {
        C375
    }
    
    to
    
    If(LEqual(Arg0, 0x0))
    {
        C375()
    }
    
11. When you've compiled successfully, the file 8510x.aml will be updated.  Check the timestamp.
    
    Load this file to your system asl /loadtable 8510x.aml.
    
12. Now reboot, if everything works, your notebook fan should be slower after a few minutes after things settled down after reboot.  WARNING: if it doesn't work and you get a blue screen during reboot.  Press F8 and choose the "use last known good" option.

Hope this works for you if you're like me and was annoyed by the fan noise.