Windows 7: NTFS Permissions - can't delete exe files?

Hello. I am using Windows 7 x64 Ultimate RTM build. When I try to delete or move exe files from another non-system permission (for example downloaded setup files), I'm getting "You require permission from (either PC1(comp. name)/nitrous(user name), PC1/Administrators or S{some long letters and numbers here}) to make changes to this folder". I have Take Ownership registry entry installed, when I run it, the error message changes to something similar.
The strange thing is that few minutes later the deleted files are gone (wtf?!), I'm using shift-del to remove them. NTFS Compression is enabled for this drive, if it matters.
I have tried putting myself as owner in advanced security settings (with putting tick on Replace owner on subcontainers and objects), however it's the same shit - it's showing me error message about PC1/Administrators..
Can anybody tell me what's going on, please?

See this thread.

Windows cannot access when trying to taking ownership

Hi Bill.... I'm guessing from this...

That it's a computer on a domain... In which case it's just not that simple. The machine will be subject to domain policy set by the server.

No, it's just a normal computer in a standard LAN network. I'm using PCx to identify computers easier.
There's no server or anything like that.
Gonna check this out, Bill2.

Logging into built-in Administrator account might fix the issue, however I don't want to log out every time I want to sort my files.

Bump?