Having 1Gb of RAM isn't really enough. If you can increase that to 1.5 or 2Gb that should give you increased performance.
Using Windows disk clean-up utility regularly will get rid of a lot of temp files, and setting IE to delete your browsing history on exit will help, but you also need a program like CCleaner to get rid of a lot more. And run chkdsk and defrag, of course. That's just Maintenance 101.
Go into IE-->Tools-->Manage Add-Ons, look for anything that's slowing down IE - toolbars and Browser Helper Objects are often to blame for sluggish IE performance.
In IE-->Tools-->Internet Options, click Settings under Delete Browsing History and make sure IE has enough memory allocated to it for storing temp files (it should be between 50Mb and 250Mb). IE can check for updated copies of cached pages automatically, whenever you visit a webpage, or once at IE startup (or never, although I wouldn't recommend that).
There are various tweaks you can run, depending on how confident you feel about changing settings. See
If IE settings have been changed, resetting to default settings might help, although this is recommended by Microsoft "only if the browser is in an unusable state". That's because you have to go in and make any changes all over again. I did it once and the increase in performance was dramatic.