"Access Denied" while replacing corrupt wininet.dll

[lyraviol]

My wife's laptop won't bootup. We've got an error:

STOP: c0000221 {Bad Image Checksum}
The image wininet.dll is possibly corrupt. The header checksum does not match the computed checksum.

So I copied a new image to a USB key and booted from a Windows install disk to a recovery console where I entered:

cd c:\windows\system32
ren wininet.dll wininet.old
copy g:\minint\wininet.dll c:\windows\system32\wininet.dll

But after the last command, I got an "access denied" error.

Can anyone help me with gaining write abilities? (I don't often use the Windows command line, and am unfamiliar with methods of changing privileges.)

[DaveC2003]

Do you have your XP CD???

If you do then boot it up at startup (use the BIOS to change the media bootup). Once the CD has been booted, Press R to repair the OS. This will save you typing out commands as this option fixes all XP files.

[lyraviol]

Dave -
It's an older CD. The laptop came without an install CD. I just held down the F2 key and it's booting up off the CD (Windows XP + Service Pack 2) right now. I'm being asked:
"Which Windows installation would you like to log onto?"
1: C:\WINDOWS
2: F:\minit

I tried them both. I get a prompt and then it just sits there:
C:\WINDOWS>
or
F:\minit>

or it seems like it's just sitting there.

Am I supposed to type in anything else?

[DaveC2003]

The link below may help.

http://www.bleepingcomputer.com/tuto...al117.html#use

[yorkypud]

At some point late at night I decided it would be clever to flash the BIOS before putting the new disc in.

NOT CLEVER

I can't get into my windows installation now. I have xp installed on a different disc to access files etc but can't get the XP disc to find the first inst to repair it. It shows up at startup as an OS option and in boot.cfg it is detected as a windows OS, but when I boot from the xp disc to repair it it's not in the list...

Any ideas wold be welcome

Nick in New Zealand