The root of the system drive is a 'SYSTEM' area. Modifiying files in it require UAC elevation. Period.
You need to put your file in a better place.
there are standard folder names for stuff like per user files and data files etc....
for one thing if you put files *only* in the proper \user\* folder then backup and restore can be done per user w/o having to backup the whole disk.
this also helps make the app work better with things like terminal server or the user trasnfer tool - move my files to a new pc thing.
it would also make the app work better in some corp. lans where users can not store files on the local drives and any files not in the users profile may be wiped at any time.
and documenting where the files are so that folks know in case they have a false alarm from a malware scanner etc...
see this in c#
Application.CommonAppDataPath <- shared files for all users of this app.
also using them takes case of the drive letter in case it's no C:
and if the user or the admin move the user folders to a different drive or map them to a network share....
then your app works better in more cases.
this aint DOS or WIndows95 anymore.
*PLEASE* follow the guildines on how apps are supposed to install and put files.