Error trying upgrading from 4.2.6 to 4.2.7 or 4.2.8

When i try to update my winscp:

"An error occurred while trying to replace the existing file: DeleteFile failed; code 5. Access Denied."

I have tried to reboot, close everything open, but without success.

Ty for your help.

Have you tried running the setup as admin?

I'm on a windows xp and my user is admin.

I need to start to read those things before post: https://winscp.net/eng/docs/reporting 8)

Let's add the needed info:

1) WinSCP version: 4.2.6 (trying to upgrade to 4.2.8 )
2) Windows version: XP SP3
3) I'm not using any scripting or gui automation
4) Full message error:
5)Steps to reproduce the error: With the 4.2.6 installed, download the 4.2.8 version and just execute the installation file and try a full upgrade.
6) I'm connected as administrator.

[]'s

Ok, the problem is not related with winscp or the installation proccess.

I was using AquaDock and that crap thing seems to keep apps running (or some reference to apps) causing the access violation. The funny thing is that the proccess manager does not show any instance of the app...

Ty.