Did you even bother looking at Google? Do yourself a favor and try to search for answers before asking people. It helps you in the fact that it makes you a better computer user because you know where and how to look for answers. It helps us because it doesn't waste our time looking for something that could have taken you 30 seconds of effort.
/end rant
see below,
This problem occurs if the Temporary Internet Files are full.
1. Start Internet Explorer
2. On the Tools menu, click Internet Options.
3. Click the General tab.
4. Under Temporary Internet files, click Delete Files.
5. When you are prompted to delete all temporary Internet files, click OK.
Delete the Internet Explorer Temporary Internet Files:
http://www.mvps.org/winhelp2002/delcache.htm
Internet Explorer Does Not Save Graphics Files in the Proper Format
http://support.microsoft.com/?kbid=260650
Internet Explorer Saves Images As Bitmaps (.bmp Files)
http://support.microsoft.com/?kbid=810978
Why can't I save .jpg, .gif or .png images in their original format in Microsoft Internet Explorer?
http://www.microsoft.com/windowsxp/e...sgroupfaq.mspx
Why IE will only let you save as BMP:
http://blogs.msdn.com/jeffdav/archiv.../08/53607.aspx
More on why ie will only let you save as bmp:
http://blogs.msdn.com/jeffdav/archiv...29/249742.aspx
If none of the above help, it may be a Content Type problem. For Windows XP, execute this command from Start/Run : Regsvr32 /i mshtml.dll