FYI:
Browser hijacking
Outlook Express security settings

Above is the Options box reached from
Outlook Express
Tools
Options
Security

Note that you should have your example of Outlook Express set up as in the image above if you wish to have images in your emails and that files that people send you actually arrive.

 
The screed below relates to a computer that has a browser, usually IE, that is acting strangely:

Firstly, run XoftSpy to see if it detects anything (it came from here: http://pctuneuptips.com/tips/remove_spyware/?id=152&gclid=CMblj7_35YwCFRrnPgodMHve8A ).

Then, since the bhr4.5.0.471.exe is a complete anti-hijack programme, run that (it came from here: http://www.filedudes.com/Browser_Hijack_Recover_BHR_-getfile-14536.html ).

Here are three files available by right-clicking to download: XoftSpy, the full version of bhr, and a different, but basic, copy should that not work. Search Google for anti-hijacking software should that prove necessary.

Here is the PC World download page for Ad Aware, Spybot, Spyware Doctor and many others. Here is SpyWare Guard, and also Spyware Doctor, the limited version, right click to run or download. For a working starter edition go here. This is the page where you can find Google pack, with several disparate programmes of use on XP and Vista computers.

SysInternals free downloads: http://www.microsoft.com/technet/sysinternals/default.mspx for lots of stuff that could help you control your computer, including a RootKit Revealer and other goodies.