Windows 98/SE/ME users: Microsoft's original advice to "unregister the shimgvw.dll" (shell image viewer) was never correct or useful on those platforms. The good news is that all current WMF exploits appear to be non-functional on the older Win9x vintage platforms . . . so you will likely be okay until Microsoft has updated your system with the next security patches. There is no short-term workaround for Windows 9x users.
This sounds to me like I should once again be glad I still run 98 on this old jalopy.