In order to switch to a directory that is located on a different drive, you need to use cd /d instead of just cd. If you do not do this, the directory will not change.
When you run a script by double-clicking on it, batch considers the current directory to be the directory where the script is currently located. Since you are not using the /d option with cd, you are running del /Q *.* on the directory where the script is located.
To fix this, you have two options:
cd /d "D:\ACT\ACTBKUP"
del /Q *.*
or
del /Q "D:\ACT\ACTBKUP"
There is no option in
forfiles to get just the most recent file;
/D +1 will return all files with a last-modified date of today or later. In order to get the most recent file and nothing else, you will need a
for /f loop:
rem /b returns just the file name and /o:d sorts the files by date
rem Since newest_file gets set for each .zip file in the directory,
rem the last file set will be the newest
for /f "delims=" %%A in ('dir /b /o:d E:\ACT_Backups\*.zip') do set newest_file=%%A
copy %newest_file% D:\ACT\ACTBKUP