If you have the 64 bit version, uninstall it and download the 32 bit version. Some users have issues with the 64bits version. Another alternative is to use XnView instead of Irfanview.
If you have the 64 bit version, uninstall it and download the 32 bit version. Some users have issues with the 64bits version. Another alternative is to use XnView instead of Irfanview.