Go to the link below and scroll down to line 12 (left column). RIGHT click on "EXE (lnk and regfile) Fix for Windows XP", choose "Save Target As " or "Save Link As", to download a reg file fix. Save the REG File to your hard disk. Double click it or right click it and choose "merge" and answer yes to the import prompt.
Click on the link below, then look to the "EXE File Association Fix", and download the .zip file to your computer desktop.. ONce there, unzip the file, then double click on the "xp_exe_fix.reg" file that is inside, choose "OK/Yes, when it asks "Are you sure?".. Restart the computer.. It should now run those problem programs and Control Panel icons.
Once that's done, because malware can cause the problem, please download, install, update, then run full system scans with both malware removal tools from the links below. Delete anything they find.:
SUPERAntispyware Removal Tool
Hope this helps.
I noticed that someone else had the same problem ie; can't open things on my desktop such as Microsoft word etc. because I get the error "Application not found'. It seems some one answered with the way to fix it but I can't find their answer.