i set up paypal express check out. i aplyed the api file and set it up as sandbox. but when i go to check out to pay in papal step 5 i get this error

Warning: main(PEAR.php) [function.main]: failed to open stream: No such file or directory in D:\hshome\accout\website.net\cubecart\pear\PayPal.php on line 11

Fatal error: main() [function.require]: Failed opening required 'PEAR.php' (include_path='D:/hshome/fab13417/maribelles.net/cubecart/pear;.;c:\PHP\pear') in D:\hshome\accout\website.net\cubecart\pear\PayPal.php on line 11

Have you checked to see if the file that it says is not there, is?