Suggestions for an affordable laptop?

I'm not sure what would be easier/cheaper: to buy a new laptop or get memory/ram cards for this one and update to windows 7.

My laptop is rather slow and freezes up at times, and I've done cleanups with help from you guys in the past. But alas, I think it might be time to put this computer away. It is pretty old, maybe from 2008 or 2004?

Anyways, I would like some suggestions for an affordable, lightweight laptop that can be used for college (i.e writing, browsing the internet) but also handle itunes downloads. Preferably 200-300 dollars or less.

Also if it possible to downgrade to windows 7 on newer laptops?

I will also provide my laptop system info just in case it is helpful in providing some advice to improve my system if it's cheaper:
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Tech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft® Windows Vista™ Home Basic, Service Pack 2, 32 bit
Processor: Pentium(R) Dual-Core CPU T4200 @ 2.00GHz, x64 Family 6 Model 23 Stepping 10
Processor Count: 2
RAM: 2009 Mb
Graphics Card: Mobile Intel(R) 4 Series Express Chipset Family, 781 Mb
Hard Drives: C: Total - 137586 MB, Free - 39879 MB; E: Total - 14999 MB, Free - 9750 MB;
Motherboard: Dell Inc., 0G848F
Antivirus: Microsoft Security Essentials, Updated and Enabled

Thank you in advance! :)