Ok, maybe this should be in the XP group, but the computer is currently
running Win7 Home Premium.

Current system:

OS Name Microsoft Windows 7 Home Premium
Version 6.1.7601 Service Pack 1 Build 7601
Other OS Description Not Available
OS Manufacturer Microsoft Corporation
System Name XXXXXXX-OFFICE
System Manufacturer Hewlett-Packard
System Model G5105uk
System Type x64-based PC
Processor AMD Athlon(tm) II X3 440 Processor, 3000 Mhz, 3 Core(s), 3
Logical Processor(s)
BIOS Version/Date American Megatrends Inc. 6.10, 02/07/2010
SMBIOS Version 2.5
Windows Directory C:\Windows
System Directory C:\Windows\system32
Boot Device \Device\HarddiskVolume1
Locale United Kingdom
Hardware Abstraction Layer Version = "6.1.7601.17514"
User Name XXXxxxx-Office\X X Xxxxx
Time Zone GMT Standard Time
Installed Physical Memory (RAM) 3.00 GB
Total Physical Memory 2.75 GB
Available Physical Memory 1.11 GB
Total Virtual Memory 5.50 GB
Available Virtual Memory 3.25 GB
Page File Space 2.75 GB
Page File C:\pagefile.sys

On-board drives:

Drive C:
Description Local Fixed Disk
Compressed No
File System NTFS
Size 584.40 GB (627,491,991,552 bytes)
Free Space 157.50 GB (169,109,729,280 bytes)
Volume Name OS
Volume Serial Number 189247B9

Drive D:
Description Local Fixed Disk
Compressed No
File System NTFS
Size 11.67 GB (12,535,721,984 bytes)
Free Space 1.41 GB (1,518,837,760 bytes)
Volume Name HP_RECOVERY
Volume Serial Number 305D9EA3

Drive E:
Description CD-ROM Disc (Rubbish - it's an optical DVD-CD ROM drive!)

PLUS 4 further external USB drives, one of them connected to the local
home network.

C & D are on the same physical SATA drive, but different partitions.

I do not have an installation disc for Win7, and if anything went
terminal, I would have to rely on drive D and a recovery CD to reinstall it.

Next week, I am getting a new computer, obviously running Windows 10.

So some questions:

1. Would it be possible to reformat just the Drive C partition and
install my own fully licensed CD copy of Windows XP plus service packs?
Or put another way, is the hardware compatible with Win XP? (This would
enable me to run a whole bunch of useful programs, and a currently
redundant Canon photo scanner, which will not run under Win 7.)

2. SP1, SP2, SP3. How many of these need installing? I guess just SP3.
Am I right?

3. If anything goes drastically wrong, or I change my mind at a later
date, is it possible to recover Win 7 from Drive D and Recovery CD ROM,
without Win 7 present on the C drive?

4. If option 3 is a definite no-go, how do I go about getting rid of
Partition D? Can't remember if the Win XP disc includes partitioning
tools. It definitely includes formatting tools. Somewhere in this house
are a suite of DOS programs that would do the job, but probably not on a
drive of that size. They date back to about 1995, and are on floppies,
but I think I might have them on a CD or an old HDD (USB caddy
available) as well.

Trust someone can up with some answers to that lot. Thanks in anticipation.

jim