Actually almost every company that sells computers currently has a form of recovery. ACER, Asus, Lenovo (IBM), Gateway (MPC branch - just went bankrupt a bit ago though...), Toshiba, HP, SunM all have a burnable DVD/CD combo to reset your computer to its default settings. Brands like Pre-MPC/Acer owned Gateway or Dell have a restore Partition- Accessable by hitting fn+f11 on bootup, older models are alt+f11 or ctrl+f11 depending.
Luckly for you, most companies have a "customer is right" policy. I had a problem occur awhile back where I had my friends HDD go out (*wink wink*), the Dell machine was out of warrenty, but I got a HDD for him (*again.. wink..*)- then called Dell and asked if I could get restore disks for his computer because the HDD had failed (*cough..). No further questions were asked- and he recieved a copy the next day (how nice of them to over night DVD's..)
I will suggest an additional three more answers:
1.) If the computer is still under warrenty, download the latest GWscan.iso and burn it to a disk. Boot with it, and write zeros (erase all ur personal data from the HDD)- full run not quick. Then take the hdd.. and drop it a few times, preferably running if you have the hardware to do that remotely with out damaging any other parts of your computer. Aka external power source protected by a surge protector. To test the damage of the HDD, you can boot to the GWscan disk again, and try to run a HDD scan (writes code in the boot sector of the HDD telling it what sectors of the HDD to ignore when read/writing- sufficently correcting 60% of normal physical damage that can be caused by physical abuse. Damage the HDD until it says it is unfixable. Take it into the store where you got the computer and get a replacement, they will get you a copy of windows with it. **Backup your data first to something else, and make sure it is under warrenty!**
2.) If the computer is out of warrenty, you could also just call in and ask the brand name company if they would send you a new copy because yours was "corrupt" and not booting- you tried to fix it but it wont work and you never got a windows cd to run a windows repair. (they will probably send you a copy then, plus no hardware damage!)
3.) Find a copy of windows, say an enterprise version that requires no cd key/activation key from your favorite place to hangout... (the web).
Switch to Linux.
(okay I lied... 4
Personally Id try 2, then 4... Sometimes just being upfront and asking will get the job done. If they sense BS they will avoid helping you. Confidence.
**Disclaimer... Do these actions at your own risk, think them out properly before hand, and ask more questions and give us more information before you make your choice of action. Once you have taken action, we can probably help you no further**