Replacing a DLL

[BigDaddy]

A week ago I repaced this "msvcrt.dll" located in "\SYSTEMROOT\SYSTEM32\" with the one from SP1 istallation cos I thought it might fix a problem I was getting w/ mIRANDA! Well it didn't, so I then I wanted to put the the original one back, but I can't cos I keep getting ACCES IS DENIED. So how do I do that?

EDIT:

I found a way.I renamed the "msvcrt.dll" and the put the original one back and Windows didn't give me any ACCES DENIED problems.

Question: How come when I wanted to delete the file I got ACCESS DENIED, but when I only renemed it it was OK??

Question2: What is this DLL even used for?

[MHz]

Pop up a dos box.

Type SFC /scannow then enter, will check your system files.

Or you could use the expand command to get the original file from cd.

E.g. expand d:\i386\msvcrt.dl_ msvcrt.dll

d is your cdrom letter.

[MHz]

System file protection will let you do something then it will reverse it. Well it should.

msvcrt.dll is a file used for visual c application. Without this, applications and such programmed in visual c will fail. Mayority of apps are programmed in visual c. Including the operating system.

[BigDaddy]

I belive I have SFP disabled:

C:\Documents and Settings\Tom>sfc /scannow
Windows File Protection could not initiate a scan of protected system files.

The specific error code is 0x000006ba [The RPC server is unavailable.
].

Since it is disabled why did it gave me access denied errors?

[oftentired]

file in use

[BigDaddy]

file in use

I understand perfectly to that part, but then why did the OS allowed me to rename the file to anything I wanted? And I wasn't even in safe mode