Spelling fixes.

diff --git a/files/drive.c b/files/drive.c
index a46a990..9b0d169 100644
--- a/files/drive.c
+++ b/files/drive.c
@@ -1069,7 +1069,7 @@
 /***********************************************************************
  *           GetDiskFreeSpaceExA   (KERNEL32.871)
  *
- *  This function is used to aquire the size of the available and
+ *  This function is used to acquire the size of the available and
  *  total space on a logical volume.
  *
  * RETURNS