You could first try to boot with a rescue disk, which may then give you the option to try a
System Restore,
as has been suggested, or boot with a
Windows setup disk and run the
Repair option from the
Windows Recovery Console.
If your PC does not work properly, then you could maybe go to a web cafe and download a boot disk or two, before burning them onto CD's.
There are quite a few available here:
www.bootdisk.com
They have all types of disks for different
OS's there, so maybe one may help you out, if you don't find anything else.
I know that
Kaspersky, also does a
Linux based rescue disk, which scans for viruses as well, but does allow you to access the files as well.
It was released in June this year, which may be some months old, but there are also other products on their site which are just a few days old,
but I'm not sure which
OS they run under at the moment, but the one I am just downloading looks like a
Windows based file, it's an
AV tool.
http://www.techmixer.com/kaspersky-rescu...using-dos/
It says on the page, that the disk is
DOS-based, but I have run it before and it was
Linux.
BTW - Also, you may not really need to
format, I would never suggest that, because, for some people, having to back up all of their data,
may take much longer, than a simple
Windows install, which on my
PC, takes about
15-18 minutes, from double clicking on
setup.exe,
to reach the
Windows Tour screen. Add another
10 minutes or so, for addtional graphics and soundcard drivers etc, and that is uually it!
It has often replaced a faulty
OS, with a fresh and clean
OS, for me. in not even half an hour,
but backing up all of your data, before
formatting, could take hours, even a day
or two, depending on how much data you have.
I think it rarely necessary, to
format, just
install Windows onto a new partiton,
or onto an existing
Windows partiton,
but into a new folder, called for example,
Windows1,
Which will
install non-destructively, leaving your previous
installation intact,
in the orignal
Windows folder,
(which you can delete at a later date if you want), with
zero data loss!
Just remember to back up any Dll's or device drivers first.,
that you may need at some point.
It will not conflict with any older
OS, as it operates in it's own
OS space.
Good luck with it.