I am running Win XP with all updates. In an administrator user account, WMP11 plays video just fine. In a limited user account, WMP11 plays the audio portion of video (DVD, MPEG2) but the video is black.
In a limited account, alternative video players play video just fine.
I have installed K-Lite Codec Pack Full; then de-installed it and installed XP Codec Pack.
I have de-installed (rolled-back) WMP11 and re-installed it.
Sounds like an overlay issue.
I don't know the exact solution but this occurs in several different situations:
1) you have multi monitor setup and you're looking at it on the secondary monitor. WMP limits it to the primary one.
2) you screenshot a video (print screen) and then view the result - you get a black box (or see live video playing if the video is still on in the background)
3) now your situation - not in admin mode.
Those are the situations I've come across.
I don't know a solution to the last one specifically, but the simplest way to fix it is to use a different player, like VLC.
Maybe someone could explain why it does this, but it's either a limitation of WMP using the graphics card, or some lame attempt at copy protection.
WinXP by itself has no codecs, even MPEG-2. That means out of the box it won't play DVDs.
If it plays under admin account, some software was installed (often that came with DVD-ROM).
If you installed the codec manually, it could have not been registered for anybody but the account installed. Example: TheaterTek will do that.
This could be checked two ways: try opening the file in graphedit in the non-admin account. Or try VLC as recommended by recneps77.
Graphedit will complain if the codec is missing. VLC should play it.
Is the user setup by any chance group policy based? With domain login? Under Citrix?
EDIT: In one case with similar behaviour deleting the HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MediaPlayer key
and reinstalling WMP11 cured the problem (from googling)...
There has never been any doubt in my mind that this problem is related to security within accounts.
I now have a work-around solution. I select WMP's startup icon, right-click and select "run as". The I select an account to "run as", enter the password, and all is well. This workaround does not survive a shutdown and restart, so it is mlldly annoying.
But there is even weirder stuff here. The account I select to "Run as" is not "Mr. Admin" but the account name that I am currently logged into -- "Mr. Limited". (Note: account names changed to protect from bad guys.)
How weird is that?
I seem to recall that XP is notorious for losing its mind when it comes to user accounts.
Sounds like a security/permissions issue to me as well. Maybe some video codec files cannot be read by the limited account. It could be almost anything from a directory to a dll or even keys in the registry. XP is a real hack when it comes to security. Win2000 was pretty good but XP security was laid to waste to get it out for the home market.
You could try to track down all the codec files, keys and other stuff that WMP needs to run and correct the permissions. That can be pretty time consuming though. Maybe there are other workarounds that will be good enough.
Robert beat me to it...sounds like a permissions issue. Is this XP Home or XP Pro?
Just a guess, but perhaps the CODEC pack is being installed into an account who's home directory has been made private. In my experience, it is possible that if an account is given a password, then the home directory is made private, even if you then remove the password (make it blank), the home directory is still protected from other accounts with that old password. The only way to fix this with XP Home is to boot into Safe mode and change the permissions.
I have a similar problem but it affects Administrator accounts and Flash Player.
On a limited account, Flash works fine.
On an Administrator account, it hangs. Easiest example: cnn dot com slash video. It shows "Loading ... " then sits there forever. I've since found many sites where similar Flash-related issues can easily be found.
I'm using XP Home. This happened on SP2 and still happens on SP3. I've upgraded my Flash version to the latest version too while trying to debug this.
Everything else works fine on the Administrator account from what I can tell. If this matters, it's an old-ish Dell Desktop with the latest BIOS for its mobo.