Those two commands look quite similar and (at the same time) a bit strange.
Both look like they're trying to remove a line containing '#', but the first one will only remove a single '#' at the start of a line and the second will only remove a single '#' anywhere in the line - neither will remove the whole line!
What you probably want is either the Perl version or the sed version.
sed is a little more lightweight than Perl. You can get it for Windows.
The sed version of the command I'd expect to do what you want:
sed -i -e '/^#.*$/d' -e 's/[ \t]*#.*$//g' kam_account_calls.txt
That'll do the whole job in place. You'll need to use GNU sed for the "-i" (inplace) functionality. The above command turns this:
a,b,c
# a comment
d,e,f
# another comment
g,h,i # test comment
j,k,l # test comment with space
into this:
a,b,c
d,e,f
g,h,i
j,k,l
Perl can do a similar thing for you, but it's a lot more heavyweight to install.