If I understand you correctly, IE does not make it self available to browse and you are using Fire Fox. The reason for that is that you have FF as your default browser. If you want to use Explorer, just type internet explorer, in the search box. When it appears, just click on it.
If that does not work it means that it is turned off.
To turn it on, in search, type turn windows features on or off.
Then when the box appears, just check internet explorer.
If you feel that it works too slow, try with the Anti Virus turned off. If that makes IE work faster, use Microsoft Security Essentials rather than your current Anti Virus.
If you have any further questions, I will be glad to assist you.