I have a inspire dell 530 it originally ran windows XP professional it was taken to the shop for minor work and when it was returned it had windows 7 on it at the time it was a welcome CHANGE. But know when the wireless INTERNET is used I am unable to access my my outlook , MSN and yahoo mail accounts I receive error message telling me I must enable cookies in my browser.  Now I have followed several diagrams to enable cookies but the computer is not responding.  I have the XP professional reinstallation CD can I reinstall XP so that I can enable cookies for the purpose of accessing my varies mail accounts?That PC should have enough  space for a dual-boot INSTALL of both Windows 7 and Windows XP. However, I will not recommend it. Yes, it works for me, but it is a hassle to do.
Instead, may I suggest you try different browsers. Besides IE, FIREFOX and Chrome, your could also try:
Opera
Lunascape 6
Sea-Monkey
And there are lots of others.
I think your problem is the browser, not the Operating System (OS).
My PREFERENCE is Firefox. I like version 33.1
http://filehippo.com/download_firefox/59294/

But if not, use Windows  7  to free up some space on the hard drive (shrink) and create a new primary partition for Windows XP. After you install XP, the Windows  7 will not boot uyntill you do a repair from a Windows  7 recovery disc. Which you would prepare ahead of time.




Did you pay the shop for this Windows 7 upgrade?  A genuine copy of Windows 7 would cost the shop around $100, if you didn't pay this then they have likely installed a pirated copy.