HELP! i can't delete this folder?

i downloaded an application from the internet. it's called Microsoft OneNote 2007 (Portable). It has Thinstall folder inside and when i open it, it has another folder named Microsoft OneNote 2007 (Portable) and when i open it there's another Thinstall folder. I keep on getting those folders (Microsoft OneNote 2007 (Portable) -> Thinstall -> Microsoft OneNote 2007 (Portable) -> Thinstall -> Microsoft OneNote 2007 (Portable) -> Thinstall -> .... and so on and so forth). I can't delete them bec my computer said "folder is not empty". I tried a file/folder shredder but it said that the file name (or something like that) is too long... what's the problem with this application? i didn't install it so it's not showing in the add/remove program... thanks for those geniuses who'll help me!