Computerhilfen.com: what is pagefile.sys will not open during virus scan

I've been working for days, cleaning trojans off my pc.  My last report came back clean with the exception of 1 warning...pagefile.sys could not be opened..in use by another program.  Is this normal, or something I should be concerned about?  Please help

Thank You,
Katheirne

Pagefile.sys is the Windows (http://www.computerhilfen.com/explanation-w-Windows.html) swap-file, it's normal, the Virus (http://www.computerhilfen.com/explanation-v-Virus.html) scan can not open this file beacause it ist used by Windows. (http://www.computerhilfen.com/explanation-w-Windows.html)