Taskmgr.exe – Application Error (0xc000012d)

Hi, I often get this error message;

taskmgr.exe – Application Error
The application failed to initialize properly (0xc000012d). Click on OK to terminate the application.

and then have to reboot. I also got the following errors today;

[Skype] ipoint.exe – Application Error The exception unknown software exception (0xe06d7363) occurred in the application at location 0x7c812afb.
[Skype] Application Error Exception EInvalidOperation in module Skype.exe at 0005B008. Cancas does not allow drawing.
[Photoshop] Could not save preferences because of a disk error.
[Photoshop?] The application failed to initialize properly (0x000012d). Click on OK to terminate the application.
[Firefox?] Thread creation error: Not enough quota is available to process this command.
[?] Ending program: Device IO Notification Manager …

I recently removed a lot of stuff trying to do a clean reinstall for Firefox, and am worried I’ve trashed something useful by mistake, or have a trojan/virus. Or possibly my copy of Windows is too old? I know my hard drive is chockablock full to bursting point, but my external drive is currently being repaired…

I managed to patch the Firefox problem by creating a new Profile, but tried to update QuickTime and got these;

The feature you are trying to use is on a network resource that is unavailable.
Click OK to try again, or enter an alternate path to a folder containing the installation package ‘QuickTime.msi’ in the box below.

The path ‘C:/Documents and Settings/User/Local Settings/Application Data/Apple/Apple Software Update/QuickTime.msi’ cannot be found. Verify that you have access to this location and try again, or try to find the installation package ‘QuickTime.msi’ in a folder from which you can install the product QuickTime.

Can’t find QuickTime.msi

Thanks for your time.

Merryn