Error 2755 after attepmted update, cannot install



This morning Windows Defender told me to update my software, which I tried to
do. I uninstalled my "outdated" version of Defender and downloaded the "new"
version from MS onto my desktop. Now I get two error messages when I try to
"The system cannot open the device or file specified." I hit Retry until I
was sure it wasn't going to work, eventually hitting Cancel.
Immediately following...
"This installer has encountered an unexpected error with this package. This
may indicate a problem with the package. The error code is 2755"
Now I have no Windows Defender on my machine, and cannot install it!
Windows Live OneCare is hollering at me to install it, yet the installer
keeps giving me this message. I tried CCleaner and "Dial-a-Fix," as thats
what another message suggested. Neither worked, so I am appealling to all
you brilliant people. Help if you can.

Dave M

Hello Markus;
Check Add/Remove for Windows Installer Package 3.1 version2
(3.1.4000.2435) If you don't have that installed you can get it here:
Then make sure your installing the Windows Defender update package from an
Admin Authority logon account.


Pl see my posting named "the system cannot open the device or file specified
" on 7/2/2006 and ses how I solved the same problem of error code 2755 on


Hi everyone.
Having the same problem but with different error message. Mine says,"Unable
to complete the update 0x8007064c. Installation source not available.
Running XP PRo SP2 with all updates. Disabled McAffe, closed all other
running programs in taskbar. Any suggestions?


Hello Deb,

Try going to WU/MU first to determine if this is a software updating issue
vs a Windows Defender bug... (and click on express)

For the benefit of the community reading this post, please rate the pºst.

I hope this post is helpful.

Let us know how it works ºut.


don d in tucson

Please provide a direct link to this post, as with so many it is difficult to

Bill Sanderson

The post referenced is more than 3 years old.

You'd be better off explaining your issue from scratch than digging that
deep into the past--the product is different now, and your OS is too.

What Windows version?

What is happening?

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