Installation problem v6 / error 1316 / tried many resolutions so far but no installat

[bercakir]

Dear all,
this is my 3rd day that I spent in front of my computer and my mind start cracking.
Firstly here is my computer config:
win7 ultimate
service pack 1
always "run as administrator".
I had bold 9000 (OS5 - BIS) and and was using/syncing with desktop manger v5.0.1 without any problem over 2year.
3 days ago bought a new bold 9788(OS6 - BIS) and my nightmares started.
Firstly, existed DM start to crashing when I connect my phone. So I downloaded from blackberry web site v6.1version.
I read necessary forums before installing and made clean uninstall for previous DM as per stated ArticleID: KB02206
plus as a medium tech savvy I run registry cleaner program to clean leftovers as I did for my all unistalls. so far noany problem about uninstall process.
when i run the installer installation starts but afterwhile it comes error 1316(a network error occured while attempting to read from the file C:\windows\installer\blackberry desktop software.msi) and installation stops androlling back process.
after that i read all the forums related 1316 error but as now no any solutions. I can't install this software to mycomputer.
here is the list of the procedures i followed so far, but i would like to remind after each installation attempt, Iuninstalled together with complete uncleaning process including with registires and all "research in motions"folders that created during installations and countless reboots.
here is the folders I deleted each time:
C:\Program Files\Common Files\research in motions
C:\ProgramData\research in motions
C:\Program Files\research in motions
in some forum manetioned another folder might be created under C:\users\****\appdata\roaming\ -but I dont found any RIM file or folder in this section.

here is the resolutions that i followed so far.
1.) all 4 resolutions explained in Article ID: KB04272
2.) used windows installer clean up app. for uninstall.
3.) i placed "desktop software.msi file inside of the C:\windows\installer folder.
4.) i run setup.exe file from extracted zip file.
5.) deleted registries from registry editor by searching ne by one.
6.) registered alt.dll for re-installs.

as I can see from the forum pages error 1316 is problem for who want to uninstall software. i just want to install latest desktop software and use my new phone and sync my contacts.
can you please check and let me know if you have any experience how to overcome about this problem ?
many thanks in advance.
Burak