Boot up problem

Hello,
My 6yr old computer (AMD Athlon 1.7GHz ;40G HD 400BB 7200rpm ATA 100; RAM256MB 133MHz DDR) OS Win XP, will not boot up. It gets as far as the desktop background, and freeze, no desktop menu to be seen. I suspected the HD. Removed it and left in the freezer overnight, still no go same result. All the fans are working. I tried a start up disk and it went through the usual checking, but no boot. Tried starting in "Safe Mode" it just flips right back to " Start Normally" over and over, but no boot. I turn off & restart and it freezes at the desktop background screen without the menu showing. No task bar no desktop icons only the bkgrnd theme picture. Mouse & Keyboard light up but no mouse action. Pointer frozen at one spot) Shift=Alt+ Delete shows Task Manager with numerous lines of "Windows Task Manager Running". Keyboard action able to move up and dn arrows, to delete lines, but can do nothing more only faint beeps when I try to highlight any of the options. All that, takes a long long time and still no mouse action.
What is your diagnosis?. The PC worked fine until I re-installed the OS to get rid of duplicate desktop icons I could not erase. There were numerous shut downs by depressing "on" button rather than the normal shut down process. Maybe I zapped the HD doing that. Help!