We're dealing with a possible infection of the Master Boot Record and we want to make sure we run the right tool, yours is a bit different variant that is showing up on the scans so just sit tight
I ran first 5 steps of your list. After clicking "Yes" to "Finished" message I'm coming back to pop-up asking me if I want to disable CD emulation drivers. No reboot request.
aswMBR version 0.9.5.256 Copyright(c) 2011 AVAST Software
Run date: 2011-05-03 17:10:29
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17:10:29.671 OS Version: Windows 5.1.2600 Service Pack 3
17:10:29.671 Number of processors: 1 586 0x401
17:10:29.671 ComputerName: BELAIRE UserName: Owner
17:10:45.890 Initialize success
17:10:53.093 Disk 0 (boot) \Device\Harddisk0\DR0 -> \Device\Ide\IdeDeviceP1T0L0-e
17:10:53.093 Disk 0 Vendor: ST3160827AS 3.42 Size: 152627MB BusType: 3
17:10:53.093 Device \Driver\atapi -> DriverStartIo 8a9c2332
17:10:55.109 Disk 0 MBR read successfully
17:10:55.109 Disk 0 MBR scan
17:10:55.109 Disk 0 TDL4@MBR code has been found
17:10:55.109 Disk 0 Windows XP default MBR code found via API
17:10:55.109 Disk 0 MBR hidden
17:10:55.109 Disk 0 MBR [TDL4] **ROOTKIT**
17:10:55.109 Disk 0 trace - called modules:
17:10:55.109 ntkrnlpa.exe CLASSPNP.SYS disk.sys ACPI.sys hal.dll >>UNKNOWN [0x8a9c24e7]<<
17:10:55.109 1 nt!IofCallDriver -> \Device\Harddisk0\DR0[0x8aa61ab8]
17:10:55.109 3 CLASSPNP.SYS[ba108fd7] -> nt!IofCallDriver -> \Device\00000066[0x8aa3b9e8]
17:10:55.109 5 ACPI.sys[b9f7f620] -> nt!IofCallDriver -> [0x8aa82b00]
17:10:55.625 \Driver\atapi[0x8aa21b60] -> IRP_MJ_CREATE -> 0x8a9c24e7
17:10:55.625 Scan finished successfully
17:11:05.000 Disk 0 MBR has been saved successfully to "C:\Documents and Settings\Owner\Desktop\MBR.dat"
17:11:05.000 The log file has been saved successfully to "C:\Documents and Settings\Owner\Desktop\aswMBR.txt"