the software that comes with the camera is pretty decent so I'd recommend it.I sometimes use a (freeware)software called raw shooters essential 2006 but unfortunately it is not being  updated anymore  so I am not sure if it'd support the raw files of 400d

I came across this  software called sharpraw,a free ware  so I am going to give it a try tomorrow

eta: I tried the software but  I don't like it.like others say canons DPP is a lot better despite the features it is lacking.

Adelaide,

As previous fellow members already said, DPP is a quite nice RAW converter, though lacking a few useful features, like a straightening tool (you can just rotate in 90� steps) and an highlight recovery adjustment. But the noise reduction is quite efficient as is the overall color/contrast/sharpness rendering of the images.
And most of all, it is FAST, compared to ACR/Bridge and even more compared to Lightroom.

One annoying point about installing Canon's tools from the original CD, is that it installs ALL of them, even those you don't need. If you downlaod the latest version of DPP on their website, you have to have a previous version already installed.

Well, that is in theory. If you're in Windows, the installer only searches the registry for a few existing keys. So if you want to install the latest version of DPP without installing all Canon's tools from your original CD, you may do the following :

WARNING : though generally not a risky operation, modifying the windows registry in any way has to be done wisely. So if you're not comfortable with such operations, please avoid the following process.

1. Create a new text document on your desktop.

2. Open this text document in notepad, and copy the following into it...

[HKEY_LOCAL_MACHINE\SOFTWARE\Canon]

[HKEY_LOCAL_MACHINE\SOFTWARE\Canon\DPP]

[HKEY_LOCAL_MACHINE\SOFTWARE\Canon\EOSViewerUtility]

[HKEY_LOCAL_MACHINE\SOFTWARE\Canon\PhotoStitch]

[HKEY_LOCAL_MACHINE\SOFTWARE\Canon\ZoomBrowser]

3. Save and close

4. Rename the new text file 'Canon.reg'

5. Right click on it and select 'merge' (which will create the previous keys in the registry, if they don't already exist)

6. Install the so called updates from Canon's web site. (they're actually the full versions - they just check the registry to confirm you've had the original software on there first).

Hope that helps
Erick