My Pc was scrwed in just one night :'(

[entity]

Last night i slept, my pc was working superb, no anitvirus was on as it expired just few days back, but it was hell to see the morning, i woke up my computer was looking as usual but when i clicked restart after that i got some error of missing .dll file for explorer i clicked ok and then my xp just didnt start, everytime giving me some stupid errors... i was having xp on other pc installed copied a whole system32 folder from there and pasted in my pc ( i think thats stupidness ) coz everytime xp was just demanding for missing files in system32 (dll and exe)!!

Well atlast after whole this i was able to run pc, but my cd rom, vga and modems were not working, reinstalled all of them but still this cd rom is not working! Guyz what could b the reason, is it someone hacked or its a virus which just blowed my system32 folder :'(

I tried to unintall and then reinstall my cd rom from device manager, searched for its driver update, but no drivers.. pls tell me what to do

Cd Rom: Atapi-CD ROM-DRIVE-56MAX

 

[entity]

well guyz 3 more things which i have come up are

1- when i click on device manager it gives me error of file MSVCR71.dll was not found.

2- Following error for cd-rom:

Windows cannot load the device driver for this hardware. The driver may be corrupted or missing. (Code 39)

3- And this error for Plug and Play BIOS Extension:

The drivers for this device are not installed. (Code 28)

 

[entity]

lolz now my cd-rom in back , i read on some sites to delete upperlimit and lowerlimit in registry did that, restarted my pc and cd-rom was back, but 1 & 3rd errors are still dere... any help ?

1- when i click on device manager it gives me error of file MSVCR71.dll was not found.

3- And this error for Plug and Play BIOS Extension:

The drivers for this device are not installed. (Code 28)