Forgive me if I'm posting this in the WRONG place, not sure where it should go!

I have a desktop with Windows XP SP2 installed. I am currently unable to open any .exe files (at least all those I've tried). Some programs (e.g. ms word) will open through an existing document. Internet explorer seems to be working fine. I had Norton AV and Firewall installed but the subscription lapsed a week ago and i hadn't got round to renewing (yes I know, but I don't use the desktop very often, so just forgot to do it). I have done a scan through Symantec online and it hasn't picked up any VIRUSES. I've tried to download spybot and adaware to check for spyware but can't get them to work because of the fact they use exe files to start up. I've done some web searches to see if anyone else has had the same PROBLEM and found a fix by DOUG Knox to restore the .exe file extension in XP but I can't open the registry because it says I'm not an administrator (even though I am).

Can someone help me?? I am not that computer literate so help in slightly less techy language would be grand.

Rachel I may get yelled at yet again, but http://www.techemperor.com/2008/01/26/cant-get-to-the-control-panel-task-manager-or-registry-editor/ this link will tell you how to re-enable your registry editting. Then you can use the fix for re-enabling your exe files. Then I suggest you go through the malware removal PROCESS outlined by the stickies in the Malware removal form here.