Hey everybody ,

I'm looking for an application that can convert multiple images from one format to another. It would be better if this certain application provided support for multiple images formats.

Has anyone got any info ?

THere are lots out there including many paint/photo editing programs.
Here's a few that will work.

Irfanview is my favorite freeware version:
http://www.irfanview.com/

AcdSee
http://www.acdsystems.com/English/index.htm

Easy Image Converter:
http://www.homeplansoftware.com/imgconv.htm

Also an alternative image manager that can handle audio/video formats as well:

Brennig's 1.4.1 (for win2k, XP and 2003)
Similar to ACDSee but Freeware.

Description by Tucows:
"This is a graphics viewer for professional artists as well as photo experts. It features a viewing engine for all common graphics file formats and includes support for alpha channels, transparency and exposure control f-stops. Tools like an advanced batch processor and converter, screen capture, lossless JPG transformation and batch printing are available. It can handle video and audio files providing automatic aspect ratio correction when playing video files, or extracting all frames, as well as scrolling a video. Brennig's includes an advanced browser supporting different view styles and play lists for managing your files. Tools like batch renaming, contact sheet creation, slideshow creation and photo e-mailing are included."

Download link

Why wouldn't you try the ReaConverter Pro? It is great batch image converter. It supports multiple image formats as i can see.

http://www.reasoft.com/products/reaconverter/

Main features:

Convert images to JPG, GIF, BMP, PBM, PGM, PNG, PPM, TGA, TIF image formats from any (BMP, DCR, EMF, GIF, ICO, JPEG, PBM, PCX, PGM, PNG, PPM, TIFF, TGA, WMF, FPX, EPS...).

Resize, crop, rotate and mirror images, change color resolution. Change image's brightness, contrast, and gamma.

Modify images using sharpen, detail, smooth, blur, and contour effects. Add transparency watermarks and borders. Make transparent PNGs and GIFs.

A command line utility allows you to process image files in console mode.

EPS and multi-page PDF, TIF and GIF support.

this programme does not combind your multiple images into one gif picture (animation) right?

Pic2Pic really does. It supports conversion to multipage GIF and PDF files, while in input you may have multiple files of different formats.
More info at http://www.pic2pic.net