Hi, thank you for posting the logs, sorry that it took so long to get to your request for help. It looks like you have more than one antivirus application installed and running at startup? MsMpEng.exe related to windows defender, and others related norton AV, both use realtime scanners, this could cause some system slowdowns, but I'm not sure how it would effect javascript, unless the applications are constantly scanning the script's for possible viruses/activx etc..

I'm not familiar with multiple user logon's with windows xp, however, all the fixes should be done via the administrator account.

I noticed that you have spybot search and destroy installed, looks like teatimer is off, as it's not showing up in the hjt log, but to be safe, ensure that teatimer is disabled in spybot search and destroy's advanced mode, under TOOLS, on the left hand side, there's "resident", ensure that "teatimer" is unchecked, prior to running any other anti-malware/anti-virus applications. Teatimer may prevent them from removing registry entries and may cause resource conflicts with other running anti-virus applications..

Your install list shows norton, and other anti-virus "online scanners" Eset, kapersky, housecall etc... It is a not so obvious general rule to only have ONE anti-virus application installed and running at a time. I'm going to recommend that you use either norton av or windows defender, but not both. There are some known issues with windows defender taking up alot of CPU resourses doing background "full scans" as well as it's realtime protection, although, I don't know enough about these applications to make a good recommendation, other than use only one or the other at a time. It's OK to use more than one AV app to cover your bases, but not more than one installed, running at a time. Also take a good look at the applications that are running in your startup entries; if you are not using them all the time, or don't need them for work, it's possible to trim down the unnecessary apps, or set the services to "manual" so that they are not starting up with windows, this way they only start when you run the application, instead of all the time in the background, taking up memory/cpu resourses..
For now, uninstall the extra anti-virus applications, including the the temporary online scanners, then post a new hijackthis log, there will be some residual entries that need to be removed.