The problem has been responded to many times. Errors are caused by a variety of reasons e.g locked files , Anti -Virus application interfering, Disk errors etc You need to look there first before blaming eraser.
1. There is now a version with runtimes
2. Updates are to the installer, compiler version and digital cert - the new cert requires a dongle to be used while signing wich means only we can sign the app.
3. yes there is press help in eraser and a PDF manual gets displayed.
>>I ran the "Erase Free Space" option
The free space erase will not remove files in the recycle bin or in hidden partitions (system restore), and it relies on the directory table being intact.
Did you format the HDD and then try to erase free space and did the erase complete without any errors...
I don't think that would be possible as the disk is changing all the time. You are better off not doing what you suggest as the drive will wear out.
Try creating an encrypted partition and storing the files there. Then erase the partition every night. If you create one the minimum size then...