You have to be patient with your HJT log. Since you bumped it several times the security techs may have overlooked it but they should notice it soon or later. Best solution when you post a message in the HijackThis section is to keep all your informations in one single post, as said in the instructions from the 5 steps before posting a log. Your post will then appear as unanswered and will be easier to notice for the security techs. In this case also, when you have problems on two different computers it's better to create one separated thread for each computer. Keep that in mind for next time but please don't create a new thread right now. It's not unusual to wait a week since many people are requesting help with their logs, but if you have no answer in a day or two starting from now then send one (and only one) private message to one (and only one) security tech to tell him about your thread.
In the mean time, try to borrow some XP CD with SP2. If you have an older CD of Windows XP without SP2 then you can create an XP SP2 CD using one of these guides :
You may not be able to burn a CD on a computer where explorer.exe isn't working so use another computer to create your slipstreamed CD if needed. Once you have an XP CD with SP2 run sfc /scannow. There are good chances that once explorer.exe is replaced by a good version your task bar and icons will be back.
It would be better to run a checkdisk as well in case the problem was caused by some corruption on the drive. Run chkdsk c: /F /R (provided c is the volume letter of your system drive). Answer no if it asks to unmount the volume then yes to schedule the scan at next restart and reboot the computer. Report if it found any error.