Possible to reinstall windows if my computer can't boot up?

Hey guys, I've been ed with trojans in my windows files and whenever I download avast to delete them, my computer is unable to boot up after the alien head.. My question is, if I choose to delete all of these infected windows files while doing the avast computer scan during the boot up process, could I then just reinstall windows with a windows disk and everything be ok?..not really sure if this is possible, but without a recovery disk/the disk that dell doesnt send out to reformat your computer when you buy the computer, how the hell else am I supposed to fix this .. Im quite clueless on what to do now.. I've talked to tech support twice and both times they basically could not do anything for me without asking me to pay $ or saying to call them back when I get a recovery disk..
HELP PLEASE
I know someone on here has to know something that could be of help
Thanks in advance and to anyone that helps

 

Do you have Alienware Respawn?

 

if you can login, get comboFix, run it and it should clean your system

 

I have alien respawn, but to do a full system restore to factory settings is unclickable..and for anything else I need to upgrade alienrespawn..
I've never heard of comboFix.. can anyone verify its validity..

 

I've used ComboFix on several computers. It works great.

Can you do a Respawn from safe mode?

 

Is there any way to remove this junk off my computer and still get windows to run? I know avast can remove it. But can anyone answer my question after I have those infected windows files deleted can I reinstall windows?

and Combo fix is not compatible with windows 7 either..

Also the only respawn points on my computer are at a time where it is already infected.. theres nothing previous to that.

 

Did you try this one http://download.bleepingcomputer.com/sUBs/ComboFix.exe
That's supposed to be the latest 64-bit

Site says it supports WIn7 32/64 http://www.bleepingcomputer.com/combofix/how-to-use-combofix

 

Does anyone know why on the alien respawn screen I cannot click on "Restore your entire system to a previous date or factory setting"? I can click on everything else except that..

 

Did you actually create a system image when you received the laptop?
Your best bet is to insert the Windows install disc and boot from DVD drive, do a complete fresh install. It's 6 hours down the drain but you'll have a fresh system. Make sure you do an Image with Respawn too.