make -C driver
make[1]: Entering directory `/home/roob/Desktop/Old-Desktop/ndiswrapper-1.37/driver'
Can't find kernel build files in /lib/modules/2.6.21.4/build;
  give the path to kernel build directory with 
  KBUILD=<path> argument to make
make[1]: Leaving directory `/home/roob/Desktop/Old-Desktop/ndiswrapper-1.37/driver'