SP2 appears to have trashed this machine

[sensei22]

Hi there...
...got a second hand machine which ran perfectly well...visited windows update site to find the computer required 71 updates which all installed sucessfully. Visited the update site again and selected to install SP2. (This computer is Win XP Home Edition) Seemed to take an awful long time, well over an hour, but there was notification that sp2 had been successfully installed and to now re-start the PC...so I did. Then the Windows loading screen just froze on loading..that's all it would do, just sat there and i watched the progress bar run and run to have nothing happen. So I have tried booting into LKGC and safe mode...none of which will work.
I did not back this system up before installing any of the updates or the service pack.
What could have caused the PC to now be unbootable and are there any suggestions I might try to remedy this?

Thanking you,
~Sensei 22~

PS...have no OS disk for this machine, so does that mean hitting F10 for recovery is pointless?

[HoustonIT]

The PC was probably chock full of malware and that hosed the SP2 install. That's been my experience.

[sensei22]

yes that is a possibility, when doing a little cleaning I noticed Malware Alarm had been installed and no doubt had the machine run for long enough, and further scans were done, more would have been found. Without a disk there's nothing I can do anyway.