Error during installing XML_RPC2
Had this very same issue
1) on the cmd line:
php -me
this will show you weather the curl extension is enabled or not. you may check your php.ini and find out that it's enable but only php -me will tell if there is a problem.
2) user pear config-showthis will list your pear configuration. make sure that ext_dir is pointing to where your php extensions are located:
pear config-show
3) make sure all your pear settings are correct otherwise use the pear config-set to correct them (e.g ext_dir)
pear config-set ext_dir \your\php\ext
If you are sure about the curl extension being enabled just install XML_RPC2 using the nodeps option
pear install --nodeps XML_PPC2
Then you should be fine.