the same ting happened to me!
the main reason i started getting this error msg was the time i updated to sp2, so here is how i get
rid of this d*** error msg.
step 1 : check out system properties -------->advanced------->performance---------->DEP (Data Execution Prevention) if its on then its the main cause of ur problem if not... then ur not lucky as i am.
step 2 : how to disable this d*** thing , its not easy though but i could handle it
first make a system disk if u dont have one already with attrib.exe file and edit app running
from dos coz u wont be able to edit the file which has the problem in it in windows.
step 3 : the file we are looking for is boot.ini which is located at c:\ the main dir of ur booting hard-disk
step 4 : startup (boot) from the system disk u made then do these commands
1. attrib -r -h -s c:\boot.ini "remove the hidden,read only, system properties from file"
2. copy c:\boot.ini boot.bak "back-up the boot.ini file"
3. edit c:\boot.ini "now here where we should start adding the option to disable DEP"
in file u will see --->
[boot loader]
timeout=4
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Microsoft Windows XP Professional" /fastdetect /NoExecute=Optin
C:\ = "Microsoft Windows"
the only command we want to change is the /NoExecute option
change the /NoExecute=Optin to /NoExecute=AlwaysOff
now just exit when prompt to save the edited file just select YES
step 5 : change attribs back to normal by this commanmd
attrib +h +r +s c:\boot.ini
step 6 : restart windows normally and i hope u get rid of this d*** thing i was havin too