trojan.metajuan won't let the computer start!

First, thank you in advance to anyone who posts. I have been searching for the answer to my question and haven't found it but I am sure it's here somewhere. So thank you for answering something you have probably already answered a billion times.

I found this site after seeing a different forum where someone was posting about removing this trojan.metajuan, but no one there helped him. He said he was able to remove the program with help from here. I am hoping you can help me as well.

I have seen the malware removal sticky. The problem is that the laptop in question won't even finish booting up, I cannot access any menus or icons to download or turn off or clean up anything.

The laptop is my husband's. I installed a new printer on our desktop and opened his computer to set it up on the network so he could print from the laptop without hooking it up. I turned it on, clicked start and then before I could click on the control panel, everything but the wallpaper disappeared. No menus, no icons, no taskbar, nothing but the wallpaper. It would not even allow me to right click on the wallpaper to pull up that menu.

I forced a shutdown, then turned it back on. It would only boot up to the wallpaper and stop. As before, no menus, no taskbar, nothing but the wallpaper.

I hit ctrl-alt-del, the task manager DOES come up. It showed no applications running, but 41 different processes. Upon suggestion of a friend, I clicked file then new task. I typed in explorer.exe, but received an error message that says the path is not valid. After clicking ok, the virus software on his laptop (I do not know what it's called and appears to be pretty generic) began to scan. It located one threat, called trojan.metajuan. I told it to delete and it said it did. Then, it said it required a restart, so that was done, however, the process then repeated itself-only booting to wallpaper, no menu, icons nothing..task manager comes up, etc.

I am unable to access anything to delete any antivirus software or firewalls. I cannot access add/remove programs to delete java, nor can I access any folders to empty or delete things.

The malware removal sticky is very clear and helpful and I will probably run all the steps on it on my own laptop and our desktop, to ensure those are clean. However, I have no idea where or how to begin with it on my husband's laptop, since I don't have access to anything but task manager.