Yeah, it's probably impossible to change this file while it's in use by the system. And if SFCFix cannot be of assistance here, I won't be able to replace it via the command prompt. Alright, I would like you to get checked in the Security Arena for malware (since this issue is associated to a known malware currently infecting a lot of users). Whoever your helper is, you can tell him/her to consult with the Windows Update Staff for the replacement of the file, if possible, with Brian (he/she will know who that is).