When pc starts up gets to first screen and message comes up about invalid cerificate for win xp and screen freezes, keyboard and mouse stops working

SOURCE: win XP problem while starting

hi

go to the recovery console and run chkdsk utility. if your problem still remain and if u have win xp setup source then repair your os.

SOURCE: My Pc was getting Windows Genuine Advantage (WGA)

you might have been using pirated sofware as most do and have updated from windows site. Reinstall windows and turn off updates or install an original version of windows.

SOURCE: Win XP - The keyboard and mouse hang

Hi,
Try booting to XP with a last Known good configuration.
After you switch on the computer, keep tapping the <F8> Key on the keyboard., you will see a list of options, select "Last known good configuration" and hit the Enter key...., Hope this works

SOURCE: I have 2 HDD's in my PC - both with Win XP Prop

Boot.ini is correct, but looks default is booting from Disk2 and partition 1 which is your G:\ 500 GB.

Try Copying boot.ini from c:\boot.ini to g:\boot.ini It might help

In your example I see missing "\" after partition(1), may be typing mistake, but in real time can generate error.

You boot.ini looks exactly same in both drive c:\ & G:\

[boot loader]
timeout=10
default=multi(0)disk(0)rdisk(2)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(2)partition(1)\WINDOWS="Microsoft Windows XP Professional" /noexecute=optin /fastdetect
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="GUY DRIVE XP Professional" /noexecute=optin /fastdetect

Note: boot.ini will be hidden and readonly file. You need to unhide the file and remote the read only option and then only you will be able to save the boot.ini file

Hope this helps