Hi sunnystaines - as you are no doubt aware IE8 comes with Windows 7 but it CAN be uninstalled and then reinstalled. It shouldn't have any effect on other windows applications. Take a look at my LINK - details for Windows 7. You would of course require another browser to be installed ie: Firefox or other to enable you to download IE8 again.
I can only suggest - I cannot advise one way or the other as I have never had to do this.