Just to be sure - several times you mention "explorer," I assume that each and every time you meant to say Internet Explorer. Right?
1) Do a complete virus scan.
2) Download and run ccleaner:
http://www.ccleaner.com/download/builds/downloading-slim. Be sure that the first three items are checked for Internet Explorer on the Windows tab; select Temporary Files under System; go to Options>Advanced, deselect the first item - temp files older than 48 hours. Any other CC selections are up to you - you may want to spend a little time on their site and read the tutorials. Re-boot and try IE again.
3) Try a reset on IE: from within IE, Tools>Internet Options>Advanced tab, reset.
4) Do you have another web browser installed - any problems with it?