Is it my disk ? or did i really f-up

[Fizics]

so as some may have noticed my first build has been plagued with problems and here i am to ask yet one more question and seek your advice

and the story begins : i came home from work and stopped at best buy to buy yet another 80mm fan to fill my case (i now have 5) i get home and check my cs:s download; 55% progress from when i left good i thought now to instal this fan i shut down windows and connect the fan. seems to work well. i push power and evreything seems to be fine untill the computer passes the post screen it then has a black screen with nothing but a little blinking underscore (_)< like that then after say 5 or 6 seconds of that an error pops up and tells me that the file C:/windows... /setup is corupt or missing and windows cant start. it tells me i need to repair windows. so i put my boot disk in and try to repair that doesnt work.

SOoo

i decide to instal windows over again i go through the process and for some crazy reson decided to convert the hdd to NFTS and while windows is installing i get an error message that says it can not continue becasue of an error with the disk. now my disk is verry old and moderatly scratched but it installed with no dificultys the first time allthough my system did hiccup a bit. but did work

ahh now that the storys outa the way my question

could a dirty/damaged windows disk cause this problem and if so why did it boot with "relativly" no problems untill this and finaly how did a system file go missing if i never touched the windows file prior to this happening

i built this on friday so i dont think theres enough time to screw up windows that much ....at least thats what i thought

would buying xp again help ? or did i royaly screw the pig on this one

if anyone understands what i just said because i know my gramar is horrible
please let me know your thoughts

 

[Nodsu]

It could be any piece of bad hardware..

Since the problems started after you installed some more power sucking hardware, it could be that your PSU just can't keep up with your fans. Try with less devices/fans connected and see if the problem goes away.

You should test your hard drive (it did say that C:\whatever file was bad, didn't it?) and RAM.

 

[Fizics]

i checked the hardrive for errors nothing and i dont know how to test my ram without windows

 

[Rage_3K_Moiz]

Download memtest from here and burn the ISO image onto a disk using a friend's computer or any other PC u can find. Then boot ur PC with this disk and let the test run overnight. This will check ur RAM for errors.
it may also be that the conversion didn't go as planned and you screwed up the file system. In that case, u will need to boot the system into DOS using a Windows 98/2000 startup disk and then format the drive from there.
About Windows XP, if u have a legal license key, then just get a friend (or do it urself if u have a spare PC or a laptop) to torrent-download a copy of XP and then use it along with ur license key to try and install again.