Compaq Desktop wont boot after virus removal

So there are "Helpers" and "Helpees" in here. Right now I'm a "Helpee!" I contracted one of the antivirus viruses. I think it was Antivirus Pro or something. I attempted to remove it and thought it was off my computer so I rebooted in safe mode and it ran great! I backed up a bunch of important files and moved some stuff over to an external. I ran avast and avg which took forever (like 24 hours). Then I tried a normal restart into windows. When it booted up I got the popups saying I was infected and needed to buy their software yada yada yada so I attempted a reboot back into safe mode and NO DICE! I got the BSOD with this error string:

0x0000007b (0xF8A4E528, 0xC0000034, 0x00000000, 0x00000000)

After much anguish and random forum recommended DOS commands I threw my hands in the air. I went into the repair console, gave it the old Format c: command and that's it. I'm assuming there are some steps I should have taken before doing that but I had really limited ability with the computer. So now I guess I have a blank Hard drive. I can get into repair console but it takes me right to the prompt of C:/> Not C:/>Windows: It told me the NTLDR is Missing press ctrl+alt+del to restart. I gave it the copy e:\I386\NTLDR C:\ and copy e:\I386\netdetect.com c:\ commands but then upon attempting a regular bootup it gave me the boot.ini corrupt attempting boot from windows (something like that) that didnt happen and I got the <windows root>\system32\hal.dll corrupt or missing, please re-install this file. error.

Anyone care to take this one on? The computer is an eight year old Compaq Presario 5000 desktop
1.3ghz Intel Celeron Processor
upgraded to 512mb Ram from 256 3 years ago
40gb ultraDMA Hard Drive
16x max DVD ROM Drive
8x max CDRW Drive with easy creator software
56k v.90 modem
Integrated direct AG 3D graphics w/up to 11mb dynamically allocated as video memory
10/100 ethernet
Microsoft Windows XP Home edition

Try this fix taken from John Barnett MVP if this don't work try this link http://xphelpandsupport.mvps.org/

There may be an occasion when you boot up your PC that you receive an error message such as HAL.DLL file is corrupt or missing. In many cases this can simply be a misconfiguration in the Boot.ini file and can easily be corrected by instigating a suitable repair.

1/ Place your Windows XP CD into your CD-ROM and Reboot your PC

2/ XP's setup program will automatically start and files will be loaded to memory

3/When you reach the Welcome to Setup screen choose the Repair option by pressing R

4/ This will start the Recovery console and the list of Windows installations will appear

5/ As you only have one installation on your PC you need to press the number which is relevant to your installations location. This, obviously will typically be 1

6/ Type in your Administrator password. If you are using Windows XP Home edition the administrator password is blank by default so simply press Enter

7/Now type bootcfg /list

8/ A list will now appear of all the entries in your boot.ini file

9/ Next type bootcfg /rebuild

10/ Your boot.ini file should now be repaired

11/ Finally remove your XP CD from the CD-ROM and then type Exit

12/ Reboot your machine to see if the the problem has been cured

Good Luck !