OK the main problems as I can see it at the moment are :

You only have 1Gb of RAM which is really borderline for windows 7
Microsoft Security Essentials is also running so you will need to disable/uninstall that

Lets empty the temp files and see if that helps a bit

Warning This fix is only relevant for this system and no other, using on another computer may cause problems

Be advised that when the fix commences it will shut down all running processes and you may lose the desktop and icons, they will return on reboot

Run OTL

[*]Under the Custom Scans/Fixes box at the bottom, paste in the following

https://dl.dropbox.com/u/73555776/OTL_Fix.GIF


:Commands
[CREATERESTOREPOINT]

:OTL
O3 - HKCU\..\Toolbar\WebBrowser: (no name) - {2318C2B1-4965-11D4-9B18-009027A5CD4F} - No CLSID value found.
O3 - HKCU\..\Toolbar\WebBrowser: (no name) - {30CEEEA2-3742-40E4-85DD-812BF1CBB83D} - No CLSID value found.

:Commands
[resethosts]
[emptytemp]
[Reboot]

[*]Then click the Run Fix button at the top
[*]Let the program run unhindered, reboot the PC when it is done
[*]Open OTL again and click the Quick Scan button. Post the log it produces in your next reply.